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Part Number


Operating voltage 


Communication type 

Modbus RS-485

Status Indicators 


Number of Switches


Number of input tag per switch

2 tags,  ON tag OFF ON tag

OFF to ON, ON to OFF Response 

10ms + 1/2 cycle

Operating temperature 

-17°-50°C (0°-120°F)

Storage Temperature

-25 ~ 85°C (-13 ~ 185°F)


5 to 95% (non-condensing)

Environmental Air

No corrosive gases permitted

PCB protection 

Conformal coating 

Enclosure Type 

Open Equipment

Connector Type for Power

5-Position Removable Terminal Block


10” X 3” X 2”



Relay board can communicate and send data to any device via open protocol Modbus RS-485 examples are PLC’s EDGE devices Industrial, PCs, HMI, Routers/firewalls and much more. 

Board has 6 board support that makes it easy to mount virtually in any position. With an additional layer of protection for the board, reliability, board has a clear protective coating to keep moisture and dust away from the board in a harsh environment.  


Tag is a Boolean, Modbus function code is 1: Read coils 

Dip switches making easy to change Modbus addressing up to 32 address via 1st five dip switches last 3 dip switches  used for baud rate 

Switch 1………LSB of Modbus Address 

Switch 2………Bit 1 of Modbus Address 

Switch 3………Bit 2 of Modbus Address 

Switch 4………Bit 3 of Modbus Address 

Switch 5………MSB of Modbus Address 

Switch 6………Not Used - Must be in ON Position! 

Switch 7………BAUD Rate Select 0 

Switch 8………BAUD Rate Select 1


Switch 7 ON, Switch 8 ON………. 9600 BAUD 

Switch 7 ON, Switch 8 OFF………19200 BAUD 

Switch 7 OFF, Switch 8 ON……… 38400 BAUD 

Switch 7 OFF, Switch 8 OFF…….. 115200 BAUD


The Modbus Address and BAUD Rate settings are read whenever the board powers up. The values are stored in internal memory. Changing the Modbus Address and/or BAUD Rate is accomplished by modifying the switch settings then cycling power to the Switch Board. The Switch BoardMUST be restarted in order for the new settings to take effect.


The 10 Pin Switch Board Interface Connector is designed to interface directly to the A&H Bernik RelayBoard MODEL: AJRB24v10MOD A “Keyed” 1 to 1, 10 Pin Ribbon Cable is connected between this interface connector on the Switch Board and the interface connector on the relay board. The interface allows the A&H Switch Board to monitor, override, bypass and otherwise place the RelayBoard into automatic mode. When connected, the A&H Switch Board and Relay Board interact with each other as described above.


If more that one board connected 6 pin header been added so you can connect daisy-chain with a ribbon cable in a matter of seconds  (sold separately) up to 10 boards


 All you need is to wire 1st Board with 5 positions removable terminal  block. Board has clear marking for power and RS-485 wiring.


Contact for volume pricing 


Switch Board RS-485

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