Omron CJ1W-ETN21 Redundant

[kevinkevin]

Hello all, has anyone configured before 2 CJ1W-ETN21 in a single rack? 

I am trying to put 2 units of ETN21 couple with my CJ2M-CPU33 to act like a redundant Modbus Master polling station, as the other party is also a redundant network.

As I read through the specifications this is what it mentioned

Number of Units that can be mounted		4 max. (including Expansion Racks)

 

Can I confirm that my configuration will be allowed?

[Jay Anthony]

Yes, Up to four CJ1W-ETN21 can be mounted to a single system.

[BobB]

No - Modbus only has one master. I have managed to organise 2 Modbus masters in a Red Lion protocol translator though - not the same.

[kevinkevin]

Hi BobB, 

If I were to install the two pieces of ETN21 cards, it will be to poll from different devices, totally isolated modbus network. That should be ok right?

[innoaloe]

1 hour ago, kevinkevin said:

Hi BobB, 

If I were to install the two pieces of ETN21 cards, it will be to poll from different devices, totally isolated modbus network. That should be ok right?

Yes, it should be OK, however we cannot really say that the device/network is redundant, since the CJ2M will have no way to switch which ETN21 is active automatically. Also if one unit fails the entire system will be failing also.

[kevinkevin]

Hi Innoaloe,

Thank you, fully understood.

Much appreciate all the answers guys

[kevinkevin]

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Edited April 30, 2018 by kevinkevin
Solved