EX-RC1 as a standalone PLC

[OSUstamm]

Has anyone ever used an EX-RC1 as a standalone PLC? I'm using a few of them to do a lot of logic in a CANbus system and was hoping they would continue to function if the CANbus was disturbed.

[Emil]

Theoretically, there is no problem to use it as stand alone PLC. But please note - there is no battery inside, so on power off it will loose all operand values. If this is not a problem...

[Blitz]

Theoretically, there is no problem to use it as stand alone PLC. But please note - there is no battery inside, so on power off it will loose all operand values. If this is not a problem...

When turned off, would the RC1 also loose the ladder program, i.e., does the application program need to get re-downloaded?

[Ash Neilson]

Blitz - The Application Program is never lost when the Unit is Powered Down, but any Operand Values are lost.

OSUstamm - Might I recommend some sort of 24vDC Battery Backed Power Supply? I've used a few in New Zealand that will basically run off Mains power all the time until the Mains is lost and then switch to the Batteries which on an EX-RC1 with a 12Ah 24v Battery you could expect over 12 hours of backup

[Blitz]

Blitz - The Application Program is never lost when the Unit is Powered Down, but any Operand Values are lost.

OSUstamm - Might I recommend some sort of 24vDC Battery Backed Power Supply? I've used a few in New Zealand that will basically run off Mains power all the time until the Mains is lost and then switch to the Batteries which on an EX-RC1 with a 12Ah 24v Battery you could expect over 12 hours of backup

Hi Ash,

Thanks for the reply.

Some more questions. Would it be possible for expansion I/O's via EX-RC1 and two Vision Controllers (e.g., V570's) all linked in CAN to implement the following:

1. EX-RC1 I/O states and operand values transmitted to two V570's? For example, 60 temperature values or 100 pump states simultaneously updated to the 2 V570's.

2. Either or both V570's sending write commands to the same EX-RC1 linked output channels and/or operands? For example, can either or both V570 send an on/off command to a relay output and/or write a numeric value to the same analog output channel?

[Ash Neilson]

Blitz,

Yes to the first and Yes to the second

1) In this case you would need to use the UniCAN Functionality. The EX-RC1 can send messages constantly to both Vision 570's. Remember with 16 MI's per UniCAN Send Function, you can send up to 512 Registers 16 MI's x 32 Messages in a single Program Scan.

2) Both Vision 570's can send UniCAN Messages to the EX-RC1 to control MI's for Analog Outputs and Output Operands for the Digital Outputs. If both Vision 570's were to change an Analog or Digital Output, the last Vision 570 to send a UniCAN Message would set the final Operand Values.

UniCAN is a very power tool within Unitronics PLC's. Combined with the EX-RC1 it's excellent!