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Having Communication problem while connecting GE relays in a loop (RS-485) SLAVE communicating with Yokogawa DCS (Ethernet) MASTER. if any of the relays goes offline or disconnected DCS starts showing IOP for all the rest of the points from all the relays.
There are 10 number of relays, including 369, 750 and 489.
1- All these are connected in daisy chain
2- Terminated in GE-multinet.
3- GE-multinet is connected with Yokogawa DCS using modbus TCP .
PREVIOUS ISSUE: the issue what we were facing here on the site was that when we tried to poll the data from all the relays using MDBUS simulator all together, it worked fine “when all the relays were energized” “ON”, but as soon as one or more that one relay in the loop turned to “OFF” (Switched the power off), we were having bad communication with rest of the “ON” relays. And we could see it in the MDBUS Simulator. Later this issue was resolved by changing the Character, and Message Time Out settings on the media converter. Because when we tested it with MDBUS and turn “OFF” some of the relays it was still polling the data from other relays without causing any communication failure with the relays those were “ON”.
Now, the issue is when we tried to communicate with Yokogawa DCS, what is happening that when DCS is trying to poll the data from all the 10 relays, while the relays are all “ON”, it works fine but immediately, when any one of the 10 relays turned to “OFF”, it loses communication with the rest of the relays.
OUR UNDERSTANDING: “AS per our understanding what is happening with DCS, it is unable to poll the data from any relay, it sticks there and doesn’t move to the next relay, means if it doesn’t get the reply from one relay it keeps on trying with the same relay and doesn’t move to the next relay to poll the data.”
QUESTION: “Our major issue is we need to make sure that all we’ve done from our side is correct and we don’t have to do anything further from that point onwards from our side, and if OUR UNDERSTANDING is not wrong then is it possible that being “stuck on trying” with the relay which is “OFF” is happening from our side???
We need you support, if you had come across any situation what we are facing here while integrating or interfacing the GE relays with any third party system.
Waiting for your positive response on it...
There are 10 number of relays, including 369, 750 and 489.
1- All these are connected in daisy chain
2- Terminated in GE-multinet.
3- GE-multinet is connected with Yokogawa DCS using modbus TCP .
PREVIOUS ISSUE: the issue what we were facing here on the site was that when we tried to poll the data from all the relays using MDBUS simulator all together, it worked fine “when all the relays were energized” “ON”, but as soon as one or more that one relay in the loop turned to “OFF” (Switched the power off), we were having bad communication with rest of the “ON” relays. And we could see it in the MDBUS Simulator. Later this issue was resolved by changing the Character, and Message Time Out settings on the media converter. Because when we tested it with MDBUS and turn “OFF” some of the relays it was still polling the data from other relays without causing any communication failure with the relays those were “ON”.
Now, the issue is when we tried to communicate with Yokogawa DCS, what is happening that when DCS is trying to poll the data from all the 10 relays, while the relays are all “ON”, it works fine but immediately, when any one of the 10 relays turned to “OFF”, it loses communication with the rest of the relays.
OUR UNDERSTANDING: “AS per our understanding what is happening with DCS, it is unable to poll the data from any relay, it sticks there and doesn’t move to the next relay, means if it doesn’t get the reply from one relay it keeps on trying with the same relay and doesn’t move to the next relay to poll the data.”
QUESTION: “Our major issue is we need to make sure that all we’ve done from our side is correct and we don’t have to do anything further from that point onwards from our side, and if OUR UNDERSTANDING is not wrong then is it possible that being “stuck on trying” with the relay which is “OFF” is happening from our side???
We need you support, if you had come across any situation what we are facing here while integrating or interfacing the GE relays with any third party system.
Waiting for your positive response on it...
