{
  "$schema": "https://raw.githubusercontent.com/nobrega8/mbmap-library/main/schema/mbmap-2.schema.json",
  "mbmap": 2,
  "vendor": "Waveshare",
  "model": "Modbus RTU Relay",
  "models": [
    "Modbus RTU Relay (8-ch)"
  ],
  "vendor_website": "waveshare.com",
  "description": "8-channel relay module with Modbus RTU over RS485",
  "revision": 1,
  "revised": "2026-10-18",
  "source": "Waveshare wiki: Modbus RTU Relay, development protocol V3",
  "sources": [
    {
      "title": "Waveshare wiki: Modbus RTU Relay",
      "url": "https://www.waveshare.com/wiki/Modbus_RTU_Relay"
    }
  ],
  "notes": [
    "Factory settings: slave address 1, 9600 baud, 8 data bits, no parity, 1 stop bit.",
    "Relays 1 to 8 are coils 0 to 7 (function codes 01, 05 and 0F). Address 0x00FF switches every relay at once and 0x01FF toggles every relay; both are write-only.",
    "The documentation lists the parity values in the UART parameter in two different orders (0x01 odd and 0x02 even in the command, the reverse in the reply); check on the device.",
    "Flash commands (0x0200 to 0x0207 flash on, 0x0400 to 0x0407 flash off) are function 05 writes whose value field is the delay in units of 100 ms (0x0007 = 700 ms); they are not listed as registers.",
    "Broadcast address 0 is accepted for writes."
  ],
  "protocol": "rtu",
  "unit_id": 1,
  "baudrate": 9600,
  "data_bits": 8,
  "parity": "N",
  "stop_bits": 1,
  "byte_order": "big",
  "address_base": 0,
  "x_status": "official",
  "registers": [
    {"name": "Relay 1", "group": "Relays", "area": "coil", "address": 0, "type": "bool", "access": "RW", "description": "1 = on, 0 = off"},
    {"name": "Relay 2", "group": "Relays", "area": "coil", "address": 1, "type": "bool", "access": "RW", "description": "1 = on, 0 = off"},
    {"name": "Relay 3", "group": "Relays", "area": "coil", "address": 2, "type": "bool", "access": "RW", "description": "1 = on, 0 = off"},
    {"name": "Relay 4", "group": "Relays", "area": "coil", "address": 3, "type": "bool", "access": "RW", "description": "1 = on, 0 = off"},
    {"name": "Relay 5", "group": "Relays", "area": "coil", "address": 4, "type": "bool", "access": "RW", "description": "1 = on, 0 = off"},
    {"name": "Relay 6", "group": "Relays", "area": "coil", "address": 5, "type": "bool", "access": "RW", "description": "1 = on, 0 = off"},
    {"name": "Relay 7", "group": "Relays", "area": "coil", "address": 6, "type": "bool", "access": "RW", "description": "1 = on, 0 = off"},
    {"name": "Relay 8", "group": "Relays", "area": "coil", "address": 7, "type": "bool", "access": "RW", "description": "1 = on, 0 = off"},
    {"name": "All relays", "group": "Commands", "area": "coil", "address": 255, "type": "bool", "access": "W", "description": "Write-only (0x00FF): 1 turns every relay on, 0 turns every relay off"},
    {"name": "Toggle relay 1", "group": "Commands", "area": "coil", "address": 256, "type": "bool", "access": "W", "description": "Write 1 to toggle the relay"},
    {"name": "Toggle relay 2", "group": "Commands", "area": "coil", "address": 257, "type": "bool", "access": "W", "description": "Write 1 to toggle the relay"},
    {"name": "Toggle relay 3", "group": "Commands", "area": "coil", "address": 258, "type": "bool", "access": "W", "description": "Write 1 to toggle the relay"},
    {"name": "Toggle relay 4", "group": "Commands", "area": "coil", "address": 259, "type": "bool", "access": "W", "description": "Write 1 to toggle the relay"},
    {"name": "Toggle relay 5", "group": "Commands", "area": "coil", "address": 260, "type": "bool", "access": "W", "description": "Write 1 to toggle the relay"},
    {"name": "Toggle relay 6", "group": "Commands", "area": "coil", "address": 261, "type": "bool", "access": "W", "description": "Write 1 to toggle the relay"},
    {"name": "Toggle relay 7", "group": "Commands", "area": "coil", "address": 262, "type": "bool", "access": "W", "description": "Write 1 to toggle the relay"},
    {"name": "Toggle relay 8", "group": "Commands", "area": "coil", "address": 263, "type": "bool", "access": "W", "description": "Write 1 to toggle the relay"},
    {"name": "Toggle all relays", "group": "Commands", "area": "coil", "address": 511, "type": "bool", "access": "W", "description": "Write 1 to toggle every relay"},
    {"name": "UART parameters", "group": "Configuration", "area": "holding", "address": 8192, "type": "uint16", "access": "RW", "description": "High byte: parity (0 none, 1 even, 2 odd, see notes). Low byte: baud rate (0 4800, 1 9600, 2 19200, 3 38400, 4 57600, 5 115200, 6 128000, 7 256000)"},
    {"name": "Device address", "group": "Configuration", "area": "holding", "address": 16384, "type": "uint16", "access": "RW", "write_min": 1, "write_max": 255, "description": "Modbus slave address, 1 to 255"},
    {"name": "Software version", "group": "Device", "area": "holding", "address": 32768, "type": "uint16", "access": "R", "scale": 0.01, "description": "100 = V1.00", "role": "firmware"}
  ]
}