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# #ccsd-water-ignition — 2025-08-28
**12:35 [Mason Radke](https://slack.com/archives/C08TVA84PD4/p1756409736476579):** @andy message recieved. as soon as i get a chance to work on this i'll let you know. Im hoping to find some time this afternoon or evening. I should be able to work on it tomorrow as well.
**13:07 [Kevin](https://slack.com/archives/C08TVA84PD4/p1756411629993589):** @andy Is there column titles in the black? I can only view, not edit.
![[F09DCCHUFDE_image.png]]
**13:07 [Kevin](https://slack.com/archives/C08TVA84PD4/p1756411669526579):** Asking because it's not clear which column is the modbus register
**19:19 [Kevin](https://slack.com/archives/C08TVA84PD4/p1756433943338589):** @andy we've made progress with the modbus addressing. it is likely that the register address will change as the IO card placement on the backplane changes (i.e. analog input 1 card 1 will not be the same as analog input 1 card 2).
**19:19 [Kevin](https://slack.com/archives/C08TVA84PD4/p1756433962605519):** Are all these sites the same card layout?
**19:20 [Kevin](https://slack.com/archives/C08TVA84PD4/p1756434006155649):** If not, once you provide that to us, can we change the card order and/or config of the Opto so we can test cards in different slots?
**19:36 [Kevin](https://slack.com/archives/C08TVA84PD4/p1756434981931769):** https://documents.opto22.com/1770_Ethernet_IP_for_SNAP_PAC_Protocol_Guide.pdf
**19:39 [Kevin](https://slack.com/archives/C08TVA84PD4/p1756435171558479):** this is telling us we can do explicit messaging to the Opto. Is this what you said wouldn't work due to network overload etc?
**19:51 [Kevin](https://slack.com/archives/C08TVA84PD4/p1756435871455589):** If we continue the modbus route, I read that the modbus registers are available from a tool in the PAC Manager program.