Wiren BoardDocumentation
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Reference · English

MWAC v.2 Modbus register map

revision 106977

Description

Legend
RO / RW Read only / Read/Write
Shown in bold Default register value
xN Multiply the register value by this factor to obtain the value in the stated units.

If omitted, assume 1

⚡ This register supports data transmission using events in Fast Modbus.
FW Firmware version that introduced the register. Blank means it has always been available.
Error: Value on error
Grey cell Service register: purpose, format and contents may change in later firmware
Input and output registers
Address Register parameters Channel Description Values FW
Dec Hex Type Access Format
0 0x0000 Coil ⚡ RW bool Relay K1 Output state 0 — off, C and NC closed,
1 — on, C and NO closed
1 0x0001 Coil ⚡ RW bool Relay K2
2 0x0002 Coil ⚡ RW bool Leak mode Leak mode state 0 — normal state,
1 — mode enabled

Note: since firmware 1.21.7, only 0 can be written to this register (see ERRMWAC2008); separate coil register 4 enables the buzzer.
3 0x0003 Coil ⚡ RW bool Wet cleaning mode Wet cleaning mode state 0 — mode disabled,
1 — mode enabled
4 0x0004 Coil ⚡ RW bool Buzzer Buzzer state 0 — off,
1 — enabled
10 0x000A Coil RW bool P1 Reset channel counter Writing 1 resets the counter (0)
11 0x000B P2
0 0x0000 Discrete input ⚡ RO bool F1 Input state 0 — off,
1 — on
1 0x0001 F2
2 0x0002 F3
3 0x0003 F4
4 0x0004 F5
5 0x0005 S6
6 0x0006 K1 button
7 0x0007 K2 button
10 0x000A Discrete input RO bool P1 Pulse-counter input state 0 — off,
1 — on
11 0x000B P2
15 0x000F Discrete Input ⚡ RO bool iVout output state 0 — normal,
1 — overloaded
20 0x0014 Discrete Input ⚡ RO bool F1 Larnitech leak-sensor health (valid only for these sensors)
21 0x0015 F2
22 0x0016 F3
23 0x0017 F4
24 0x0018 F5
25 0x0019 S6
6 0x0006 Holding RW u16 Relay states at power-on 0 — set output to safe state,
1 — restore last state
8 0x0008 Holding RW u16 Fail-safe timeout. To disable fail-safe behavior, configure the Output action on entering Safety Mode and Input control in Safety Mode registers s
1 — 65534 (10)
9 0x0009 Holding RW u16 F1 Digital input mode

3: interaction disabled,
4: edge control,
5: leak sensor (default for F1–F5),
6: digital input or button (default for S6)

10 0x000A F2
11 0x000B F3
12 0x000C F4
13 0x000D F5
14 0x000E S6
20 0x0014 Holding RW u16 F1 Input debounce time. Adds response delay and applies to every digital input mode. ms
0­ — 2000 (50)
21 0x0015 F2
22 0x0016 F3
23 0x0017 F4
24 0x0018 F5
25 0x0019 S6
32 0x0020 Input ⚡ RO u16 F1 Input activation counter
33 0x0021 F2
34 0x0022 F3
35 0x0023 F4
36 0x0024 F5
37 0x0025 S6
38 0x0026 K1 button
39 0x0027 K2 button
452 - 455 0x01C4 - 0x01C7 Holding RW u64 Unix time Seconds since midnight (00:00:00) on 1 January 1970, adjusted for the controller time zone
464 0x01D0 Input ⚡ RO u16 F1 Short-press counter
465 0x01D1 F2
466 0x01D2 F3
467 0x01D3 F4
468 0x01D4 F5
469 0x01D5 S6
470 0x01D6 K1 button
471 0x01D7 K2 button
480 0x01E0 Input ⚡ RO u16 F1 Long-press counter
481 0x01E1 F2
482 0x01E2 F3
483 0x01E3 F4
484 0x01E4 F5
485 0x01E5 S6
486 0x01E6 K1 button
487 0x01E7 K2 button
496 0x01F0 Input ⚡ RO u16 F1 Double-press counter
497 0x01F1 F2
498 0x01F2 F3
499 0x01F3 F4
500 0x01F4 F5
501 0x01F5 S6
502 0x01F6 K1 button
503 0x01F7 K2 button
512 0x0200 Input ⚡ RO u16 F1 Short-then-long-press counter
513 0x0201 F2
514 0x0202 F3
515 0x0203 F4
516 0x0204 F5
517 0x0205 S6
518 0x0206 K1 button
519 0x0207 K2 button
522 0x020A Holding RW u8 F1 Leak-sensor type. Used only for mode 5 set in registers 9–14 0 — normally open (NO),
1 — normally closed (NC) 		1.22.0
523 0x020B F2
524 0x020C F3
525 0x020D F4
526 0x020E F5
527 0x020F S6
544 - 607 0x0220 - 0x025F Holding RW u16 Registers of the mapping matrix for short presses. Used only in Digital input or button mode set in registers 9–14
608 - 671 0x0260 - 0x029F Holding RW u16 Registers of the mapping matrix for long presses. Used only in Digital input or button mode set in registers 9–14
672 - 735 0x02A0 - 0x02DF Holding RW u16 Registers of the mapping matrix for double presses. Used only in Digital input or button mode set in registers 9–14
736 - 799 0x02E0 - 0x031F Holding RW u16 Registers of the mapping matrix for short-then-long presses. Used only in Digital input or button mode set in registers 9–14
800 - 863 0x0320 - 0x035F Holding RW u16 Registers of the mapping matrix for rising edges. Used only in Edge control mode set in registers 9–14
864 - 927 0x0360 - 0x039F Holding RW u16 Registers of the mapping matrix for falling edges. Used only in Edge control mode set in registers 9–14
930 0x03A2 Holding RW u16 Relay K1 Safe-state configuration 0 — off,
1 — enabled
931 0x03A3 Relay K2
932 0x03A4 Leak mode
938 0x03AA Holding RW u16 Relay K1 Action on entering Safety Mode 0 — do nothing,
1 — set output to safe state
939 0x03AB Relay K2
940 0x03AC Leak mode
946 0x03A2 Holding RW u16 Relay K1 Input control in Safety Mode 0 — do not block,
1 — block in Safety Mode,
2 — allow only in Safety Mode 		1.22.0
947 0x03A3 Relay K2
948 0x03A4 Leak mode
950 0x03B6 Buzzer
952 0x03B8 Holding RW u8 Buzzer behavior when a leak sensor triggers 0 — leave unchanged,
1 — enabled 		1.22.0
954 0x03BA Holding RW u8 Audible leak-alarm duration (s) 0...60 (0),
0 — no timeout 		1.25.0
953 0x03B9 Holding RW u8 Safe-mode effect on anti-seizing 0 — allow operation in Safety Mode,
1 — postpone until the next day 		1.24.0
955 0x03BB Holding RW u8 Anti-seize protection interval days
1 - 60 (30) 		1.24.0
956 0x03BC Holding RW u8 Hour of day for anti-seize protection 0 - 23 (0) 1.24.0
957 0x03BD Holding RW u8 Anti-seize cycle duration s
10 - 120 (60) 		1.24.0
958 0x03BE Holding RW u8 Relay K1 Action at start of anti-seize protection 0 — do nothing (function disabled),
1 — turn off/on,
2 — turn on/off 		1.24.0
959 0x03BF Holding RW u8 Relay K2
960 0x03C0 Input RO u8 Relay K1 Last anti-seize protection status 0 — completed successfully,
1 — in progress: closing,
2 — in progress: opening,
3 — interrupted,
4 — never run,
5 — postponed: Safety Mode,
6 — postponed: leak,
7 — postponed: water flow 		1.24.0
961 0x03C1 Input RO u8 Relay K2
962 0x03C2 Input RO u16 Relay K1 Days until next anti-seize cycle 0 — scheduled today
0xFFFF — not set 		1.24.0
963 0x03C3 Input RO u16 Relay K2
977 0x03D1 Holding RW u8 Relay K1 Effect of water flow on anti-seize scheduling.
Uses the same channel's counter: K1 — P1 input; K2 — P2 input 		0 — allow operation while water is flowing,
1 — postpone until the next day 		1.27.0
978 0x03D2 Holding RW u8 Relay K2
964 0x03C4 Holding RW u16 Service register to disable the buzzer. Value does not persist after restart. 1 — disabled,
0 — enabled 		≥ 1.21.1
965 0x03C5 Holding RW u16 Service register to output a system clock on the RS-485 connector. Writing this register interrupts communication for the duration specified in register 966. 1 — RTC crystal frequency,
2 — 8 MHz / 128 frequency
966 0x03C6 Holding RW u16 Service register specifying system-clock output duration on RS-485. 1 — 20 s
968 0x03C8 Holding RW u16 Service register to start measuring voltage drop across the BAS70-06 diode in series with the battery. Used in production to estimate battery consumption without external power.

Measurement procedure:
1. Write 1 to this register; the device restarts
2. Wait 0.1 s for entry into the bootloader
3. Disconnect power
4. Wait 2.2 s for measurement completion
5. Restore power
6. Wait 2.8 s for startup and initialization
7. Read register 969
969 0x03C9 Input RO u16 Service register containing the voltage drop across the BAS70-06 diode in series with the battery. Follow the preceding register's procedure to obtain a reading. mV; below 300 mV is considered normal
970 0x03CA Input RO u16 Battery-voltage service register. Measured once at startup. Without a battery, reads approximately 0.6 V due to circuit limitations mV
971 0x03CB Input RO u16 Battery condition 2 — excellent,
1 — normal,
0 — depleted
974 0x03CE Holding RW u16 Restore valve state after the leak is resolved 0 — disabled,
1 — enabled
975 0x03CF Holding RW u16 Wet-cleaning mode timer min
1 — 360 (20)
976 0x03D0 Input RO u16 Remaining wet-cleaning time min 1.24.0
1062 - 1063 0x0426 - 0x0427 Input RO u32 P1 Channel pulse counter
1064 - 1065 0x0428 - 0x0429 P2
1066 0x042A Holding RW u16 P1 Channel pulse weight. Common meters produce one pulse per 1, 10, 50 or 100 litres. Check your meter's technical documentation. L/pulse
1­ — 10000 (1)
1067 0x042B P2
1068 - 1071 0x042C - 0x042F Input RO u64 P1 Channel volume counter ×0.001, m3
1072 - 1075 0x0430 - 0x0433 P2
1076 - 1079 0x0434 - 0x0437 Holding RW u64 P1 Initial channel counter value L (0)
1080 - 1083 0x0438 - 0x043B P2
1100 0x044C Holding RW u16 F1 Long press time ms
500 — 5000 (1000)
1101 0x044D F2
1102 0x044E F3
1103 0x044F F4
1104 0x0450 F5
1105 0x0451 S6
1140 0x0474 Holding RW u16 F1 Second press waiting time ms
0 — 2000 (300)
1141 0x0475 F2
1142 0x0476 F3
1143 0x0477 F4
1144 0x0478 F5
1145 0x0479 S6
8260 - 8323 0x2044 - 0x2083 Holding RW u16 Registers of the mapping matrix for the rising edge of a leak-sensor signal. Used only in Leak sensor mode set in registers 9–14
65402 0xFF7A Holding RW u16 Service register for configuration reset. The device restarts after reset. 1 — perform reset ≥ 1.21.1
Connection settings, firmware version and other service registers
Address Register parameters Description Values Note
Dec Hex Type Access Format
Connection settings
110 0x006E Holding RW u16 RS-485 baud rate.
RS-485 connection parameter settings 		×100, baud
12 — 1200 bit/s,
24 — 2400 bit/s,
48 — 4800 bit/s,
96 — 9600 bit/s,
192 — 19200 bit/s,
384 — 38400 bit/s,
576 — 57600 bit/s,
1152 — 115200 bit/s
111 0x006F Holding RW u16 RS-485 parity setting 0 — no parity (none),
1 — odd,
2 — even
112 0x0070 Holding RW u16 RS-485 stop bits
See: stop-bit tolerance 		1, 2
128 0x0080 Holding RW u16 Device Modbus address (details)
Device model and firmware version
200-205 0x00C8 - 0x00CD Input RO string Device model
206-219 0x00CE - 0x00DB Input RO string Device model extension. Read 20 registers (200–219) to obtain the device model Only in firmware supporting Fast Modbus
220-244 0x00DC - 0x00F4 Input RO string Firmware build commit hash and branch name (2 characters per register)
250-265 0x00FA - 0x0109 Input RO string Firmware version
266-269 0x010A - 0x010D Input RO u64 Serial number extension
270-271 0x010E - 0x010F Input RO u32 Serial number
290-301 0x0122 - 0x012D Input RO string Firmware signature
320 0x0140 Input RO u16 Firmware version in numeric format (details) MAJOR Only in firmware supporting Fast Modbus
321 0x0141 MINOR
322 0x0142 PATCH
323 0x0143 s16 SUFFIX
324-325 0x0144 - 0x0145 Input RO u32 Firmware version in numeric format Only in firmware supporting Fast Modbus
326-327 0x0146 - 0x0147 Input RO u32 Firmware version in big-endian format Only in firmware supporting Fast Modbus
Other information
104-105 0x0068 - 0x0069 Input RO u32 Uptime since boot seconds
120 0x0078 Holding RW u16 Reboot device without saving state Any non-zero value reboots the device
129 0x0081 Holding RW u16 Enter firmware update mode for 2 minutes Any non-zero value enters firmware update mode
330-337 0x014A - 0x0151 Input RO string Bootloader version
130 0x0082 Holding RW u16 Disable Status LED 0 — enabled
1 — disabled
131 0x0083 Holding RW u16 Enter firmware update mode using the current communication settings.
To check whether the firmware and bootloader support this feature, read this register. If reading succeeds and returns 0, the feature is supported. 		Writing 1 enters firmware update mode
113 0x0071 Holding RW u16 Delay before replying to a Modbus request ms
0…254 (0) 		Only in firmware supporting Fast Modbus
114 0x0072 Holding RW u16 Continuous reading across register gaps 0 — disabled
1 — enabled
2 — enabled persistently across reboots 		Only in firmware supporting Fast Modbus
121 0x0079 Input RO u16 Current supply voltage mV
122 0x007A Input RO u16 Minimum supply voltage since boot, without averaging mV
125 0x007D Input RO u16 Current supply voltage, without averaging mV
119 0x0077 Input RO u16 Minimum microcontroller supply voltage since boot, before averaging mV
123 0x007B Input RO u16 Microcontroller supply voltage mV
124 0x007C Input RO s16 Internal microcontroller temperature x0.1, °C
304-319 0x0130-0x013F Input RO string Device batch number.

Available only on devices manufactured from 21 January 2026.

From firmware 1.23.0
64256-64383 0xFB00-0xFB7F Input RO u16 FlashFS: free space per page bytes From firmware 1.23.0
64384-64511 0xFB80-0xFBFF Input RO u16 FlashFS: total size of current files per page bytes
64512-64639 0xFC00-0xFC7F Input RO u16 FlashFS: page fragmentation 0…100 %
0 — all data is current,
100 — no current data
64640-64767 0xFC80-0xFCFF Input RO u16 FlashFS: page erase counter
65402 0xFF7A Holding RW u16 Reset device settings to defaults. Communication settings are retained.
The device reboots after the reset. 		Writing 1 resets the settings From firmware 1.22.0
65500 0xFFDC Coil RW bool Service register for visually testing indicator LEDs Writing 1 switches on all indicator LEDs Since firmware 1.26.0
65504 0xFFE0 Input RO u16 Maximum stack usage bytes
0 — stack corrupted 		From firmware 1.23.0
65505 0xFFE1 Input RO u16 Free RAM bytes
65506 0xFFE2 Input RO u16 Used RAM bytes
65507 0xFFE3 Input RO u16 Stack size bytes
65508 0xFFE4 Input RO u16 Cause of last MCU reset 1 — LPWR,
2 — WWDG,
3 — IWDG,
4 — SFT,
5 — POR,
6 — PIN,
7 — OBL,
8 — V18PWR 		From firmware 1.23.0
65509 0xFFE5 Input RO u32 Firmware update counter From firmware 1.23.0