KMK179 - Wifi Optical Probe User Manual

The KMK179 connects the optical port of a meter to your software over Wi-Fi, on one TCP connection. In the automatic modes the probe handles the optical line by itself, so meter reading software that works with a cable probe can use it as it is; in command mode your software sets the line and can ask the probe about itself (Chapter 4).

Figure 1.1 - From the meter to your software

1.1 The products

Product	Optical head	Board	Working mode chosen with
KMK179	IEC 62056-21	KMK119 board with a Wi-Fi module	the mode switch

The KMK179 is the Wi-Fi member of the family. The hardware is shown in Chapter 2; how it works as it leaves the factory is in Chapter 4. Firmware for a particular meter or protocol is available as a project-specific variant (Chapter 10.4).

1.2 This manual

This manual describes firmware v6.4 290926 and our software abcZ 4.2.0 for Windows (Chapter 12). A probe with the legacy firmware behaves differently in places; Chapter 14 lists the differences.

• Chapter 2 hardware, Chapter 3 connecting, Chapter 4 working modes, Chapter 5 the optical line;
• Chapter 6 integrating the probe in your own software, Chapter 7 every command, Chapter 8 status and identity, Chapter 9 stored settings;
• Chapter 10 firmware updates, Chapter 11 power and battery;
• Chapter 12 abcZ;
• Chapter 14 what is new since the legacy firmware, Chapter 15 troubleshooting;
• Appendix A replies, refusals and stored settings, Appendix B service information.

The KMK179 is built on the KMK119 board, with a Wi-Fi module in place of the Bluetooth module: it has the same mode switch and an IEC 62056-21 optical head. The working modes are in Chapter 4.

2.1 Front

Figure 2.1 - KMK179 front

• The button switches the probe on; press it again to switch it off.
• CHARGE: VIN GOOD is on while a charger with a good voltage is connected; CHARGE is on while the battery charges and goes off when it is full (Chapter 11.1); CHARGE turns red in the cases of 2.3.
• POW. is on while the probe is on.
• LINK blinks fast while the probe is not on a Wi-Fi network, blinks slowly when it is on the network and no client is connected, and stays on while a client is connected - for example while software has the probe's TCP port open. TX and RX flash when data goes to and comes from the meter.
• SPEED: MODE 1 - MODE 4 show the switch position (2.2.1).

2.2 Mode switch, USB port and optical head

2.2.1 Mode switch and USB port

Figure 2.2 - KMK179 sides

On the side are the USB charging port - USB Type-C or Micro-USB, depending on the hardware version - and the two mode switches. The switch positions are printed on the case:

The probe reads the switches only at power-on. After you change them, switch the probe off and on again. What each position does is in Chapter 4.

2.2.2 Optical head

Figure 2.3 - KMK179 optical head (IEC 62056-21)

The KMK179 has an IEC 62056-21 optical head with a flat face that sits on the meter's optical port, and holds on the meter with an N38 magnet.

Figure 2.4 - KMK179 on the optical port of an IEC meter

2.3 The red LED

The CHARGE LED turns red in three cases:

The KMK179 joins your Wi-Fi network and waits for one TCP connection, on port 2015 as it leaves the factory. Commands and meter data travel on that connection (Chapter 6.5); there is no serial port to fall back on.

A new KMK179 first has to learn the name and the password of your network. You give them to it once with abcZ, over the optical port, on the Service port page (Chapter 12.4); from then on the probe joins your network every time it is switched on.

3.1 Is the probe on your network?

Watch the LINK LED: it blinks fast while the probe is not on a network, blinks slowly when it is on the network and no client is connected, and stays on while a client is connected. The probe takes its address from your router (DHCP); you find it in the router's list of clients by its MAC address, which starts with 00:04:3E.

3.2 Try the command channel

Any TCP client that sends bytes given in hex is enough - for example a terminal program such as RealTerm. Connect to the probe's address, port 2015, and send:

FE FE 42 4C 55 45 30 38 4E 31 A1 FF

The probe answers with its battery voltage in millivolts as ASCII text, followed by 00 (0xA1). The frame is explained in Chapter 6.1.2; the same test in Python and C# is in Chapter 6.6.

3.3 Read a meter

Use meter reading software that can open a TCP connection: give it the probe's address and port 2015, and choose the working mode that suits the meter (Chapter 4). For example our ZR meter reading software.

The working mode decides what the probe does on the optical line: follow an IEC 62056-21 or DLMS/COSEM session by itself, pass data at a fixed speed, or take commands from your software (command mode). The command frames of Chapter 7 are answered in every mode; only the line commands need command mode.

Figure 4.1 - The working modes and how each product selects them

4.1 KMK179 - mode selected by the switch

The 4-position switch selects the working mode, and the mode LEDs show the position. The switch is read only at power-on: switch the probe off, move the switch, switch it on again. Commands 0xD1 - 0xD4 restart the probe, so the switch is read after them too.

The table describes the standard firmware variant; other variants are project-specific. The variant is stored in the probe and changed only with 0xD1: loading a different firmware image does not change it.

KMK179 is the KMK119 board with a WiFi module: the switch, the LEDs and the modes are the same.

4.2 Reaching command mode

To check the mode from your software read 0xDA: field 3 is the working mode and field 9 the switch position (field list). The stored choices are kept by a factory reset and by firmware updates over the air - Chapter 9.

The line is the optical connection between the probe and the meter. In the automatic and fixed modes the probe sets the line itself; in command mode your software sets it.

5.1 The line in each working mode

5.2 Setting and keeping the line in command mode

5.2.1 The line commands

The command byte itself carries the value: 0x30 - 0x38 set the speed (300 - 38400 baud), 0x40 - 0x44 the data format (7E1, 8N1, 8E1, 8O1, 8N2), and 0x50 / 0x51 hold or release a break. They take effect at once and send no reply. Outside command mode they are refused with 15 (reason 10).

5.2.2 Keep your line settings

A line setting you send lives in RAM. In command mode the probe applies the STORED line settings again every time a new connection is made. If the connection drops and you reconnect, the line is back at the stored speed and format - a job that carries on without noticing reads garbage. For a long job, store the line settings with 0xE0 before you start.

In the IEC and DLMS auto modes a new connection restarts the automatic sequence at 300 baud.

5.3 Optical speed limits

IEC 62056-21 optical communication goes up to 19200 baud, and up to 19200 baud the probe was measured byte-exact in both directions. 28800 and 38400 baud are outside the standard. They can work with a given meter, but may need a higher optical sensitivity (0xD0), and bytes can be lost - in our measurements in the probe-to-meter direction. Use them only with a protocol that checks its own data (for example with a CRC), and test with your meter first.

How your own software talks to the probe. The rules below are the same over the WiFi TCP connection; transport notes are in 6.5 and working code in 6.6.

6.1 The command channel

6.1.1 Meter data and commands on one channel

Everything you send goes to the meter over the optical line, except a command frame: the probe recognises its 12-byte frame, answers it itself and does not pass it on. On firmware v6.x the frame is recognised in every working mode, so you can query the probe without stopping a reading session. The legacy firmware of the KMK179 takes commands in command mode (switch position 4).

6.1.2 The command frame

Figure 6.1 - The 12 bytes of a command frame

Only byte 11 changes. Example - read the firmware name (0xA0):

FE FE 42 4C 55 45 30 38 4E 31 A0 FF

6.1.3 Replies

Most commands reply with ASCII text or a status byte, followed by 00. The status bytes are 06 (ACK, accepted), 15 (NACK, refused - 0xDC tells why) and 00 (end of the reply): Appendix A.2. These commands reply differently:

6.2 Commands with a parameter

Figure 6.2 - Form A and Form B: the bytes and the 1 s parameter window

6.2.1 Form A - ACK first, then the parameter (0xC3, 0xD0)

The probe answers 06 00, waits up to 1 s for one parameter byte, and answers 06 00 again when the value is applied. Without a parameter it answers 15 00 after 1 s and nothing changes. Send the parameter in the same write as the frame.

Set the sensitivity to 30 (0x1E):
->  FE FE 42 4C 55 45 30 38 4E 31 D0 FF
<-  06 00           frame accepted
->  1E              the value - send it in the same write as the frame
<-  06 00           value applied

The same frame without the value:
->  FE FE 42 4C 55 45 30 38 4E 31 D0 FF
<-  06 00
    ... 1 s ...
<-  15 00           nothing changed; 0xDC then reads "208,7"

6.2.2 Form B - parameter after the frame, or a query (0xD1 - 0xD4)

After the frame the probe sends nothing and waits up to 1 s for one parameter byte. If it arrives, the probe answers 06 00, stores the value and restarts. Send the frame alone to read the value: after 1 s the probe answers 15 00 and then the value. The 15 00 is normal for a query - read on to the second 00.

Set switch position 3 to 19200 8N1 (0xD2 = 2):
->  FE FE 42 4C 55 45 30 38 4E 31 D2 FF
->  02              the value - within 1 s; nothing comes back before it
<-  06 00           stored; the probe restarts

Read the value:
->  FE FE 42 4C 55 45 30 38 4E 31 D2 FF
    ... 1 s ...
<-  15 00 32 00     "2" = 19200 8N1

Value out of range:
->  FE FE 42 4C 55 45 30 38 4E 31 D2 FF
->  09
<-  15 00           nothing changed; 0xDC then reads "210,9"

Back to the default of the firmware (v6.2 and later):
->  FE FE 42 4C 55 45 30 38 4E 31 D2 FF
->  FF
<-  06 00           stored value cleared; the probe restarts

6.2.3 Never send 0xFE as a parameter

0xFE always starts a new frame, so it is never taken as a parameter. After 0xC3 or 0xD0 the probe answers 15 00 (reason 8) and reads the 0xFE as the start of the next frame; this is why 254 cannot be sent to them. Send each frame and its parameter in one write, and do not start the next command before the parameter has gone.

6.3 Command mode and restarts

6.3.1 Commands that need command mode

The line commands and the factory reset (0x30 - 0x38, 0x40 - 0x44, 0x50, 0x51, 0xE1) work only in command mode, because changing the line in the middle of an automatic session would break it. In any other mode they are refused with 15 (reason 10). All other commands work in every mode.

6.3.2 Commands that restart the probe

0xD1 - 0xD4 store their value, answer 06 00 and restart the probe about 50 ms later, so the new setting is applied cleanly. A firmware update also ends with a restart. After a restart:

• open a NEW TCP connection before the next command - the old socket can stay open, but do not rely on it;
• send 0xA2 again if your job needs it (6.4).

6.4 A good session

1. Open the connection (TCP port 2015).
2. Read 0xA0: the product, the firmware and so which commands exist (Chapter 8).
3. Read 0xDA: every setting in one reply.
4. Work. Check every reply; after a 15, ask 0xDC why.
5. If the job has pauses without a connection, send 0xA2: without a connection the probe sleeps after 60 s.

Do not send commands while a meter transfer is running: no data is lost, but the reply is inserted into the meter data at that point, and your software may not find it.

6.5 Transport notes

Commands and meter data travel on one TCP connection to the probe, port 2015 (production setting). There is no serial profile to fall back on: a probe that is not on your network cannot be reached.

The WiFi module drops an association after about 120 s without traffic and joins again later: keep some traffic on the link, and reopen the socket before you call it a fault. A reply can arrive several seconds late, because the module may hold its delivery; allow about 10 s before you treat a command as unanswered.

6.6 Code examples

Both examples read the name, the battery and two settings, then set the sensitivity. Both examples were run on a KMK179 with firmware v6.4 290926 (only the address changed); adjust the address.

6.6.1 Python

"""Talk to a KMK179 WiFi optical probe from Python over its TCP connection."""
import socket
import time

FRAME = bytes.fromhex("FE FE 42 4C 55 45 30 38 4E 31")


def command(sock, code, param=None, wait=3.0):
    """Send one command frame (and an optional parameter byte); return the raw reply."""
    data = FRAME + bytes([code, 0xFF])
    if param is not None:
        data += bytes([param])              # the parameter goes in the same write
    sock.sendall(data)
    reply = b""
    end = time.monotonic() + wait           # the WiFi module can hold a reply for a few seconds
    while time.monotonic() < end:
        try:
            chunk = sock.recv(1024)
        except socket.timeout:
            continue
        if not chunk:
            break                           # the probe closed the connection
        reply += chunk
    return reply


def text(reply):
    """The ASCII text of a reply, without the 00 terminators."""
    return reply.replace(b"\x00", b"").decode("ascii", "replace")


def main(address="192.168.1.50", port=2015):
    with socket.create_connection((address, port), timeout=5) as probe:
        probe.settimeout(0.1)
        print("name     :", text(command(probe, 0xA0)))
        print("battery  :", text(command(probe, 0xA1)), "mV")
        fields = text(command(probe, 0xDA)).split(",")
        print("mode     :", fields[2], "  switch position:", fields[8])
        print("0xD0 = 30:", command(probe, 0xD0, 30).hex(" "))   # 06 00 06 00 = applied


if __name__ == "__main__":
    main()

6.6.2 C# (.NET)

// Talk to a KMK179 WiFi optical probe from C# over its TCP connection.
using System;
using System.Collections.Generic;
using System.Net.Sockets;
using System.Text;
using System.Threading;

static class ZtTcp
{
    static readonly byte[] Frame = { 0xFE, 0xFE, 0x42, 0x4C, 0x55, 0x45, 0x30, 0x38, 0x4E, 0x31 };

    // Send one command frame (and an optional parameter byte); return the raw reply.
    static byte[] Command(NetworkStream link, byte code, int param = -1, int waitMs = 3000)
    {
        var data = new List<byte>(Frame);
        data.Add(code);
        data.Add(0xFF);
        if (param >= 0)
            data.Add((byte)param);              // the parameter goes in the same write
        link.Write(data.ToArray(), 0, data.Count);
        var reply = new List<byte>();
        var buffer = new byte[1024];
        var end = DateTime.UtcNow.AddMilliseconds(waitMs);   // the WiFi module can hold a reply
        while (DateTime.UtcNow < end)
        {
            while (link.DataAvailable)
            {
                int n = link.Read(buffer, 0, buffer.Length);
                for (int i = 0; i < n; i++)
                    reply.Add(buffer[i]);
            }
            Thread.Sleep(20);
        }
        return reply.ToArray();
    }

    // The ASCII text of a reply, without the 00 terminators.
    static string Text(byte[] reply)
    {
        return Encoding.ASCII.GetString(reply).Replace("\0", "");
    }

    static void Main()
    {
        using (var client = new TcpClient("192.168.1.50", 2015))
        {
            NetworkStream probe = client.GetStream();
            Console.WriteLine("name     : " + Text(Command(probe, 0xA0)));
            Console.WriteLine("battery  : " + Text(Command(probe, 0xA1)) + " mV");
            string[] fields = Text(Command(probe, 0xDA)).Split(',');
            Console.WriteLine("mode     : " + fields[2] + "  switch position: " + fields[8]);
            Console.WriteLine("0xD0 = 30: " + BitConverter.ToString(Command(probe, 0xD0, 30)));
        }
    }
}

Every command is a 12-byte frame: FE FE 42 4C 55 45 30 38 4E 31, the command byte, then FF. Only the command byte changes. This chapter describes firmware v6.4; where older firmware behaves differently, the card says so in its "On legacy firmware" row. Refusal reasons and status bytes are in Appendix A; service commands are in Appendix B.

Y = works in every working mode. C = command mode only (refused with 15 in other modes). - = not on this product: no reply. (-) = accepted, but has no effect on this product.

7.1 Identity and status

7.1.1 0xA0 — Read the firmware name

Read the firmware name and version. Send it first: it tells you the product, the working mode and the firmware generation.

The nine-character name code

The live characters show what the probe is doing now, so they can differ from the code in the firmware file name - that is not a fault. Only the version and date (for example v6.4 290926) must match your firmware package.

7.1.2 0x9E — Read the image identity

Read the build identity of the running firmware image.

NOTE:

Compare it for EQUALITY with the value published for your firmware package; it is not a version order.

7.1.3 0xDA — Read all settings

Read every setting in one reply.

NOTE:

New firmware only ADDS fields at the end: read the fields you need by position and ignore fields you do not know.

Fields 1 - 11

Fields 12 - 32 are service diagnostics: Appendix B.1.1.

7.1.4 0xDB — Read the capabilities

Ask which features this firmware image has.

NOTE:

Test single bits - never compare the whole number with a constant. Read it as an unsigned 32-bit value. Firmware built before August 2026 does not answer.

Capability bits

7.1.5 0xDC — Why was it refused?

Ask why the last command was refused (NACK).

7.2 Line settings

7.2.1 0x30 - 0x38 — Set the line speed

Set the speed of the optical (meter-side) line. The command byte itself is the speed.

NOTE:

28800 and 38400 baud are above what the optical standard covers: they may need a sensitivity adjustment (0xD0) and bytes can be lost. Use them only with a protocol that has its own checksum (Chapter 5.3).

7.2.2 0x40 - 0x44 — Set the data format

Set the data format of the optical line. The command byte itself is the format.

7.2.3 0x50 - 0x51 — Break on / off

Hold the optical transmit line in the break state, or release it.

NOTE:

For meters that need a break condition before a session.

7.3 Power and battery

7.3.1 0xA1 — Read the battery voltage

Read the battery voltage in millivolts.

NOTE:

The lowest voltage measured since power-on. Measured after the regulator, so a nearly empty battery can still read high. The useful range is 3000 - 3200 mV. Charge the probe before a firmware update.

7.3.2 0xA9 — Read the battery charge

Read the battery charge as a percentage.

NOTE:

Linear between 3000 mV (0%) and 3200 mV (100%); the same caveat as 0xA1.

7.3.3 0xA2 — Keep the probe awake

Stop the probe from entering its low-power sleep.

NOTE:

Without a connection the probe otherwise sleeps after 60 s. This does not stop the auto power-off (0xC3). Send it again after anything that restarts the probe.

7.3.4 0xC2 — Switch off

Switch the probe off, as with the power button.

7.3.5 0xC3 — Set the auto power-off time

Set how long the probe waits without activity before it switches itself off.

WARNING:

Do not store 0 or a short time with 0xE0: at power-up the probe would switch itself off before a client can connect.

NOTE:

Factory value 240 s. The countdown runs only while no connection is open; a connected probe without traffic switches off after about 11 minutes (Chapter 11.3). 254 (0xFE) cannot be sent: 0xFE always starts a new frame (Chapter 6.2.3).

7.4 Optical head

7.4.1 0xD0 — Set the optical sensitivity

Set the sensitivity of the optical receiver.

NOTE:

Factory value 30 (49 on older units). Raise it step by step for meters with a weak optical output; lower it if you see duplicated bytes from reflections. On KMK119, KMK139 and KMK179 stay at or below 0x55. 254 (0xFE) cannot be sent: 0xFE always starts a new frame (Chapter 6.2.3).

7.5 Working mode

7.5.1 0xD1 — Select the firmware variant

Select the firmware variant on KMK119 / KMK139 / KMK179.

NOTE:

Loading a different firmware image does NOT change a variant set with this command. A probe whose variant was never set uses the variant of the loaded image.

7.5.2 0xD2 — Switch position 3 line settings

Choose the line settings of switch position 3.

7.5.3 0xD3 — IEC baud change-over mode

Choose the IEC 62056-21 baud change-over mode used by the IEC auto mode.

7.5.4 0xD4 — DLMS start framing

Choose the data format at the start of a DLMS session in the DLMS auto mode.

7.6 Settings

7.6.1 0xE0 — Store the settings

Store the current session settings as the power-on defaults.

NOTE:

Stores sleep, auto power-off, sensitivity, line speed and data format. The working-mode commands 0xD1 - 0xD4 store themselves. The stored bytes: Appendix A.3.

7.6.2 0xE1 — Factory reset

Restore and store the factory settings.

NOTE:

Restores: sleep on, auto power-off 240 s, sensitivity 30 (49 on older units), 300 baud 7E1. It does not change the working mode or variant (0xD1 - 0xD4).

7.7 Wireless module

7.7.1 0xBD — Restart the wireless module

Restart the Bluetooth or WiFi module of the probe.

NOTE:

Reconnect when the probe is back on the network (LINK LED blinking slowly). Useful when the connection is up but data no longer passes.

7.7.2 0xBC — Factory-reset the wireless module

Return the Bluetooth or WiFi module to its own factory configuration.

WARNING:

This takes the probe OFF your network and keeps it off: the module goes back to its own network name ("Amped AP") and to UDP, so no TCP connection comes back. The reset is applied at the next power-up. Use it only when you can reach the probe over the optical service line to write the network settings back.

A few read-only commands tell you what a probe is and what it is doing. They work in every working mode and change nothing, so you can send them at any time - except in the middle of a meter transfer (Chapter 6.4).

8.1 Reading the firmware name

The name has a nine-character code, the version and the build date. Example "N70221134 v6.4 290926":

The legacy firmware of the KMK179 answers with a free-text name instead, for example CC_WF52_v6.0 280722. That version number is not a v6.x version: KMK179 firmware v6.x starts at v6.2 and always has the nine-character code.

The firmware file name carries the same code, but only with the defaults of the image. Characters c2 - c5 are read from the probe at start-up, so after a mode change, or on a probe that still has the legacy bootloader, the name differs from the file name. That is not a fault: only the version and the date must match.

8.2 Asking for a feature

Before you use a feature that not every firmware has, read 0xDB and test its bit. Never compare the whole number with a fixed value: a newer firmware adds bits. Firmware without the capability read (the legacy firmware) does not answer 0xDB at all - treat silence as "no extra features".

The probe keeps two kinds of settings. Knowing which is which saves surprises after a power cycle, a factory reset or a firmware update.

9.1 Storing and restoring

0xE0 stores the session settings as they are now; they become the power-on settings. 0xE1 restores and stores the factory values - sleep on, auto power-off 240 s, sensitivity 30 (49 on older units), 300 baud 7E1 - and works only in command mode. Neither touches the identity settings, so a factory reset never changes what kind of probe it is.

Every stored byte: Appendix A.3. The line settings are also re-applied from the stored values at every new connection (Chapter 5.2.2).

A firmware update keeps the probe's stored settings and its identity (Chapter 9). Update a KMK179 with abcZ on a Windows PC, over Wi-Fi (section 10.2). A KMK179 with firmware v6.x takes an update at any time and in every working mode; you do not need to switch it off and on. It has no other update path. A KMK179 with the legacy firmware cannot be moved to v6.x over the air: its first v6.x firmware is loaded with a programmer (Chapter 14.2.1).

10.1 Before you update

10.1.1 Which file

Figure 10.1 - Which file for which KMK179

For each firmware image the KMK179 package has an _OTA.bin, which abcZ loads over Wi-Fi as a staged update: the probe keeps running its firmware until the new one is complete and checked. Every KMK179 with firmware v6.x has the A/B bootloader, so there is no _LEGACY.bin.

Download the file for your model from its product page on probeformeters.com (Latest Firmware), or use the one we supply with your probes; abcZ refuses a file made for another model. Loading a firmware image does not change a stored working mode or variant (Chapter 4).

10.1.2 Charge the probe first

A probe with firmware v6.x refuses to start an update while its battery is below 3100 mV (0xA1). abcZ skips such a probe and tells you why.

10.2 Update with abcZ (Windows)

Open the probe in abcZ (Chapter 12.1) and choose the Firmware page. Then:

1. Press Choose a .bin... for each model and pick the firmware file (Figures 10.2 and 10.3); abcZ refuses a file made for another model. Section 10.1.1 tells which file to use.
2. Press Review and update firmware (Figure 10.4). The review shows which file goes to which probe, the update path, the link, the number of packets and an estimate of the time; nothing has been sent yet (Figure 10.5).
3. Leave Check module defaults before the update ticked: abcZ compares the module with our standard and writes only what differs.
4. Press Start the update. abcZ shows the progress of every probe. A probe whose battery is below 3100 mV is skipped, with the reason - charge it first.
5. When the update ends, abcZ reads every probe again (Figure 10.6). A green row means the probe came back and reported the new firmware itself; a red row means the check could not be completed: open the probe and read it, and see the Log page (Chapter 12).

Figure 10.2 - Firmware: one image per model (shown with a KMK119)	Figure 10.3 - Choose a .bin: the _OTA.bin file for the model (shown with a KMK119)

Figure 10.4 - Every model has an image (shown with a KMK119)	Figure 10.5 - Review before anything is sent (shown with a KMK119)

Figure 10.6 - Updated and verified (shown with a KMK119)

10.3 Time and interruptions

10.3.1 How long it takes

Connecting and the final check add some time. abcZ shows its own estimate in the review, before anything is sent (section 10.2).

10.3.2 If an update is interrupted

With the A/B bootloader the running firmware stays until the new one is complete and checked; a power loss during the switch-over is completed at the next power-up. An interrupted staged update can simply be started again.

10.4 Project-specific firmware

Firmware for a particular meter or protocol - for example another layout of the working modes - is available as a project-specific variant; contact us. Update such a probe only with the file we supply for it.

11.1 Battery and charging

The KMK179 has a 1200 mAh battery. Charge the probe with the cable that comes with it, from any USB charger or PC port with a USB Type-A socket. Depending on the hardware version the probe has a USB Type-C or a Micro-USB port. While the probe charges its charge LED is on; the LED goes off when the battery is full.

How long a charge lasts depends on the work. In our test with firmware v6.4 290926 a PC read an IEC meter through the probe every 10 seconds over Wi-Fi (one TCP connection, working mode IEC auto; the meter was simulated): a KMK179 worked about 9 hours on a full charge.

11.2 Battery level

0xA1 reads the battery voltage in millivolts and 0xA9 as a percentage; both give the lowest voltage measured since power-on. The probe measures the voltage after its regulator, so a nearly empty battery can still read full: the useful range is 3000 - 3200 mV, and 0xA9 maps this range to 0 - 100 %. Below 3000 mV the CHARGE LED turns red, and it changes back once the battery reaches 3050 mV. Below 3100 mV a firmware update does not start (Chapter 10.1.2).

11.3 Auto power-off

The probe switches itself off to save the battery. Without a connection it waits 240 s without activity (the factory value; set it with 0xC3). While a connection is open that countdown does not run; instead a probe that stays connected without any traffic switches itself off after about 11 minutes. Every byte in either direction - from your software or from the meter - starts both again. 255 turns both off. Both wait while a firmware update or a module setting is in progress.

11.4 Sleep

Without a connection, a probe with sleep on goes into a low-power sleep after 60 s and switches its mode LEDs off. A freshly programmed probe has sleep off; a factory reset (0xE1) turns it on and 0xA2 turns it off (Appendix A.3). Sleep does not switch the probe off - auto power-off does.

abcZ is our Windows program for the probes. It finds them, shows what they report about themselves, changes their settings and updates their firmware - of one probe or of many at a time. Download it from the product page of your probe or directly: abcZ-4.2.0.zip. The archive holds one program file, abcZ.exe, that runs without installation. It needs a PC with 64-bit (x64) Windows 11 in a version Microsoft still supports, or with a Windows 10 Enterprise LTSC or IoT Enterprise edition that Microsoft still supports: abcZ is built on .NET 10, and these are the Windows versions .NET 10 supports.

This chapter shows abcZ in normal mode. Admin mode is for service use: changes made there can make the probe unreachable. Contact us before using it.

abcZ runs in one window. If you start it a second time, no second window opens: the open one comes to the front and says "A second abcZ was started and closed - this window is the one in use". To work with several probes, open them side by side in its Devices list.

12.1 Find your probes

Under SOURCE choose "Connect by IP address (KMK Wi-Fi)", type the probe's address and port (2015, Chapter 3) and press Connect.

Video - reaching a KMK179 over Wi-Fi with abcZ:

Watch the video at probeformeters.com/download/abcz-kmk179-connect.mp4.

Each column of the list is a value read from the probe; a dash means that the probe does not have the command. Double-click a row, or select it and press Open device, to open the probe's pages.

12.2 A probe's pages

12.2.1 Overview

The Overview page shows what the probe reports about itself: the firmware name and date, the nine-character name code decoded character by character (Chapter 8.1), the link, the battery, how an update is protected, and the meter line - the speed and framing the optical line uses now and the one it starts with at power-on. Read again reads it all anew.

12.2.2 Settings

The Settings page lists the probe's settings with the command behind each one. On the device is the value read from the probe; choose a New value and press Write and verify. What writing does tells what happens: 0xD1 - 0xD4 restart the probe, so abcZ waits, reopens the port and reads the value back before it reports success (Chapter 6.3.2); the other settings apply at once and last until the next restart unless you store them. Dimmed rows are commands this probe does not have; hover one to see why. The settings themselves are in Chapter 4, Chapter 5 and Chapter 9.

The Meter line box works in command mode only: choose the speed and framing and press Apply to line. Store as power-on default (0xE0) keeps the current settings for the next power-on. Hold the line in break (0x50) and Release (0x51) start and end a break on the optical line. Factory defaults (0xE1) and Turn off (0xC2) do what the commands do.

Figure 12.1 - Settings (shown with a KMK119)

12.2.3 Module

On a KMK179 the page is called Wi-Fi module and shows the probe's Wi-Fi module: its identity and its network settings. Press Read all from the module; where a value differs from our standard, abcZ fills in our standard as the New value, and Write to the module applies it. SSID and PassPhrase are the only fields you can type in normal mode. Check both before you write: with a wrong value the probe cannot join the network and can no longer be reached over Wi-Fi - contact us.

When the probe cannot be reached over Wi-Fi - it has never joined a network, or its network settings are wrong - its module is read and written over the optical port instead (Chapter 12.4).

12.2.4 Diagnostics

Diagnostics reads the probe's counters and its state. The counters only count up, so a number alone does not tell when something happened. To see what an action costs, press Read counters, then Use as baseline, do the action you suspect - for example a meter reading or a firmware update - and read again: the change column shows the difference. Forget baseline returns to plain readings. Below the counters every state value carries its own note on the screen. When you contact us about a problem, send us a screenshot of this page.

Figure 12.2 - Diagnostics, top of the page (shown with a KMK119)

12.3 Update and log

12.3.1 Update the firmware

The Firmware page updates the firmware of the open probe over Wi-Fi. The steps, with the screens, are in Chapter 10.2.

12.3.2 Log

The Log page lists every step abcZ took, probe by probe; Only what went wrong narrows the list and Copy everything copies it. abcZ also writes abcZ.log and abcZ.previous.log next to its program file: send both with a problem report.

The Wi-Fi PassPhrase written from the Module page appears in the log only by its length, for example "(hidden, 16 chars)".

12.4 Service port

The Service port page talks to the KMK179's Wi-Fi module directly, through a USB optical probe placed face to face with the KMK179's optical port, without the probe's firmware in between. Use it to put a new KMK179 on your network, or one whose network settings are wrong:

1. Switch the KMK179 off, set the switch to position 3 (Chapter 2.2.1) and switch it on: the module is reached only in mode 3.
2. Place a USB optical probe face to face with the KMK179's optical port and plug it into the PC. No program may be connected to the KMK179 over the network meanwhile: the module's answers do not reach the optical port then.
3. On the Service port page choose the PORT - the list shows the plugged-in KMK optical probes, each with its identity -, choose the Wi-Fi module as MODULE and keep the LINE at 9600 8N1, the line of switch position 3 unless you changed it (0xD2). Press Open on the Module page.
4. abcZ opens the module as a device of its own, on its Module page, and reads it over the optical probe: "... values read over the service port". Type the SSID and the PassPhrase of your network and press Write to the module. abcZ writes them, reads each one back and restarts the module: "... written and read back; the module restarted to use them".
5. Switch the KMK179 off, set the switch back to the position you work in and switch it on. Its LINK LED blinks slowly when it is on your network (Chapter 3.1).

If the module does not answer, abcZ names the three usual causes: the KMK179 is not in mode 3, the optical probe does not sit face to face with its optical port, or the line speed differs. To change a value once more, press Read all from the module first: abcZ compares what you type with its last reading of the module. For a KMK179 that is open in abcZ over Wi-Fi the page also offers Read on the Module page: the module is then read through the optical probe and written over the probe's own Wi-Fi link.

Video - putting a KMK179 on the network over the service port (the PassPhrase is blurred):

Watch the video at probeformeters.com/download/abcz-kmk179-service-port.mp4.

ZRobo, our free Android app, connects to probes over Bluetooth only. The KMK179 is reached over Wi-Fi, so ZRobo does not connect to it: use ZR meter reading software or your own TCP client (Chapter 6).

This chapter is for anyone who already uses KMK179 probes with the legacy firmware - the firmware that answers 0xA0 with a free-text name such as CC_WF52_v6.0 280722 (Chapter 8.1). KMK179 firmware v6.x starts at v6.2: the v6.0 and v6.1 entries below reached the KMK179 with v6.2. The chapter lists what changed in each release, which commands are new, and what to watch when you move a probe to v6.x.

14.1 What changed

14.1.1 Release history

14.1.2 Command differences

The customer commands of this manual, compared with the command list of the legacy firmware. Service counters are in Appendix B.1.2; commands used only by service tools are not listed. The "On legacy firmware" row of each card gives the details.

14.1.3 What works differently

Also different: 0xE0 answers with two bytes (06 00); the line settings return to the stored values at every new connection (Chapter 5.2.2); loading a different firmware image does not change a stored variant or function (Chapter 4).

14.2 Moving to v6.x

14.2.1 Updating legacy probes

A KMK179 with the legacy firmware cannot be moved to v6.x over the air: its old bootloader refuses v6.x images (a safety check), and there is no legacy update file for this product. The first v6.x load needs a programmer; after that, updates run over WiFi.

14.2.2 Compatibility

The first v6.x load of a KMK179 is done with a programmer, which sets the stored settings to the defaults of the loaded image (Chapter 9). Check the working mode and the settings after the load.

Start with the probe itself: is it switched on, charged (Chapter 11) and in the working mode the meter needs (Chapter 4)? Then look up what you see below.

15.1 A command is refused

A refusal is 15 (NACK). Right after it, 0xDC tells which command was refused and why (Appendix A.1).

15.2 A command gets no answer

• Check the frame: 12 bytes - FE FE, "BLUE08N1", the command, FF (Chapter 6.1.2). Bytes that are not a complete frame go to the meter.
• While a firmware update runs, the probe answers only 0xA0, 0xDA, 0xDB and 0xDC; other commands get no answer until the update ends.
• While abcZ reads or writes the settings of the wireless module (Chapter 12.2.3), the probe answers no other command until that is finished.
• The probe is not on your network: watch its LINK LED (Chapter 3.1).
• The connection dropped after about two minutes without traffic, or the reply is late: Chapter 6.5.
• After 0xBC the probe has left your network and cannot be reached over Wi-Fi - contact us.
• With the legacy firmware, use command mode (switch position 4, Chapter 6.1.1).

15.3 Readings fail or data is garbled

Check that the optical head sits flat on the meter's optical port and that the working mode and line suit the meter (Chapter 4, Chapter 5). Then adjust the optical sensitivity with 0xD0 - a higher value is more sensitive: raise it one step at a time for a meter with a weak optical output, such as a battery-powered meter; lower it one step at a time when bytes arrive doubled because of reflection. Try a reading after each step, and store the value that works with 0xE0.

15.4 Frequently seen

A.1 Refusal reasons

After a refusal (15), 0xDC returns the command code and one of these reason codes. Some reasons come from service commands (firmware update, module configuration).

A.2 Status bytes

A.3 Stored settings

Bytes 0 - 4 are session settings: they change in RAM and survive a power cycle only after 0xE0. Bytes 5 - 9 are written at once by their own command and are kept by a factory reset (Chapter 9).

For service and production. Your own software does not need these.

B.1 Dump, counters and stored bytes

B.1.1 Settings dump fields 12 - 32

Continues the field list of 0xDA.

B.1.2 Diagnostic counters

Plain queries with no parameter; they work in every mode and are cleared by a restart. Read 0x9D first: every counter is counted since power-up.

B.1.3 Stored bytes 10 - 13

Continues Appendix A.3. Written by the probe itself; do not write them. Bytes from 14 on hold internal copies (module type, and on the KMK179 a pending module reset and the module address).

B.2 Returning to the legacy firmware

A KMK179 cannot be returned to the legacy firmware over the air: the v6.x bootloader of this product refuses it, and there is no legacy update path. Returning needs a programmer - contact us.

B.3 Engineering changes from the legacy firmware to v6.x