PM4RO - 4 Relay Output Module

The PM4RO module has 4 normally open/ normally closed relay outputs. These modules may be used when a higher drive capability is required, or when isolation between outputs are required.

Each output can be individually switched on or off, or all outputs can be set up at the same time by writing a single number to the output register which represents the status of all outputs.

The module may be used as either a slave or master on the Modbus network. When used with a PC or PLC the module will be configured as a slave. When used with a PM16DI module in a point-to-point configuration, the DIP switch 9 must be turned on to set the module up as a master. In this mode the PM4RO module will automatically read the information from the PM16DI module and write the input status to the outputs.

An output watchdog timer can be configured to switch off all the outputs if there has been no communications with the module for up to 255 seconds. A value of 0 seconds will disable this timer and the outputs will remain in the last programmed state.


Digital Inputs



Relay - 1 x Form C

Max Load Current

0.5Aac / 1Adc.

Max load Voltage

220Vac / 28Vdc

Isolation (Field & Logic)


Watch dog output timer

Disable or 1-255 sec adjustable

Status Indication

LED for each channel

Power supply (Logic)

 + 24Vdc

PM4RO - 16 Digital Input Module

Order Codes

  • PM4RO- PROMUX 4 Relay Output Module

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