Is it possible to swap Yokogawa centum communication cards ACM11 and ACM12 with plant live without causing a shutdown? We currently have the need to expand the number of subsystems our Centum CS communicates with. We currently have ACM11 in place and are considering removing it and replacing with ACM12 with plant live. What are the associated implications. Kindly assist.

 

Hi -

Removing the ACM11 card will cause all data it is reading to be declared bad - and likely change to "zero" state.
You will need to review your usage of this data to determine whether you can tolerate this outage for the time period it takes you to change the card & reprogram the serial port.

It sounds you you want to add more stations to the serial link (change from RS232 to RS485) - I recommend you expand by retaining the existing ACM11 and installing the ACM12 as additional (card goes into nest goes into node etc).

I do not recommend multiple slaves on a single Yokogawa serial link - while it is "supported", and we use this feature regularly - it is a last resort as there are many undesirable features with this configuration.

Regards, PB