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WDT-1 watchdog relay, three-quarter view

WDT-1

Watchdog relay that restarts devices when Modbus communication stops

Normally open
Relay contact
250 VAC
Max. relay voltage
RS485
Modbus RTU
9 to 36 VDC
Supply voltage

Overview

Where it works

WDT-1 is a controller that keeps the modules at a site working in environments with poor power quality, where voltage surges, harmonics and other anomalies on the supply lines cause failures. It has a built-in relay that operates for a programmed time when communication on the Modbus bus stops. It monitors the operation of a GWU module and runs on 9 to 36 VDC.

Mounting: 35 mm DIN rail (IEC 60715)

  1. Automatic switching of the relay contacts when Modbus communication stops (writing 0 to register 441)
  2. Automatic restart of devices that have stopped working
  3. Automatic switching off of the relay (for 2 seconds) at a set interval (30 to 1800 seconds)
  4. Periodic timer (30 to 1800 seconds) with a pulse output
WDT-1 watchdog relay, three-quarter view
WDT-1 watchdog relay, three-quarter view

Datasheet

Technical data

Function

Watchdog module
Modbus module that monitors the operation of a GWU module

Power supply

Supply voltage
9 to 36 VDC
Consumption
max. 35 mA

Relay output

Relay type
Electromagnetic relay
Contact type
Normally open
Max. operating voltage
250 VAC
Max. contact current
5 A (AC-3) / 1 A (AC-1)

Communication

Interface
RS485
Protocol
Modbus RTU
Baud rate
9600, 19200, 57600, 115200default 9600
Parity
8N1, 8E1, 8O1, 8N2default 8N1

Environment

Operating temperature
-20 to 60 °C
Storage temperature
-20 to 80 °C
Relative humidity
below 95 %, non-condensing

Status LEDs

  • GreenOnExternal power supply to the controller present

Integration

Modbus registers

The full register map of the module. Filter by address, name or description.

Input registers

RegisterNameTypeDescriptionValuesDefault
301Device typeuint16_tDevice type, WDT-1 = 10991099
302HW versionuint16_tHardware version of the device030 = HW version 3.0
303SW versionuint16_tSoftware version of the device030 = SW version 3.0
304Serial number high byteuint16_tSerial number of the device, high byte
305Serial number low byteuint16_tSerial number of the device, low byte

Holding registers

RegisterNameTypeDescriptionValuesDefault
401Device slave addressuint16_tModbus device address127127
402MODBUS baud rateuint16_tModbus communication baud rate0 to 3 0 = 9600 1 = 19200 2 = 57600 3 = 1152000
403Modbus parityuint16_tParity check mode0 to 3 0 = 8N1 1 = 8E1 2 = 8O1 3 = 8N20
441Counteruint16_tClear the counter to prevent a restartWrite 0 to clear the counter0
442Thresholduint16_tTime to reset, in seconds30 to 18001800
443Testuint16_tTest, switches the relay offWrite 1 to switch the relay off for 2 seconds0

Installation

Dimensions and connection

WDT-1: Dimensions in mm
Dimensions in mm
WDT-1: Connection diagram
Connection diagram
WDT-1: On a 35 mm DIN rail
On a 35 mm DIN rail
Transport, warranty and maintenance
Transport and storage
Protect the module from shocks and avoid extreme conditions. Store it in the original packaging.
Warranty
Two years from the date of manufacture against manufacturing defects. Modifications to the product after the publication date of its documentation release the manufacturer from liability. The manufacturer is not responsible for typographical or other errors in the documentation.
Maintenance
Under normal conditions the module needs no maintenance. Light dirt comes off with a dry or slightly damp cloth; for heavier dirt use non-aggressive cleaning products. Always disconnect the power supply first, keep liquids out of the housing and reconnect the power only when the module is completely dry.

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