11/25/2021 2:13 PM | |
Joined: 11/8/2021 Last visit: 5/9/2024 Posts: 2 Rating: (0) |
I have 41 devices (Pick-IQ K30 Lights) all connected in series via 485 2-Wire duplex connected to a "CP PTP RS485/455 HF", I am using an individual master for them all as they all have an individual ID from 1 - 41. i also have an additional master with an "MB_Adds" as 195, when reading with this address it allows me to press a button and read the ID of the touched button, i can do this for all buttons to ensure i have given them an ID. I can write to 1 - 9 of the devices when i give it data and set the request on the master, any more then 9 it doesn't work, it gives me a status 16#7002, and keeps the "BUSY" on. I am only activating 1 master at a time to ensure i have no coiling data, i have checked the mode as well as hardware config, is there a valid reason why after 10 i have no control over. ------------------------------------------------------------------------------------------ |
Last edited by: Adam9900 at: 11/25/2021 14:13:37Last edited by: Jen_Moderator at: 11/26/2021 08:12:31New subject after splitting |
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11/25/2021 5:54 PM | |
Joined: 3/28/2010 Last visit: 9/21/2024 Posts: 1056 Rating: (213) |
You mention "485 2-wire duplex". Modbus 2-wire 485 is always simplex operation. It probably makes no difference unless you've checked a configuration box somewhere for 'duplex' operation that can't be implemented in a Modbus RTU protocol. Post #2 at the thread: I do not understand the 2nd Master (the caveat about one and only one master on an RTU bus is the RULE), but I would try physically disconnecting its wiring entirely from the 485 network bus and then trying the primary master to see if the 10 slave limitation still exists. Is a 3rd wire/conductor being used as a signal ground for all devices? What is being done with termination resistors? Where in the network bus wiring are the masters? at each end? in the middle somewhere? Are the slaves connected directly to the network bus with incoming wiring pair and outgoing wiring pair all on the same terminals or is there 'stub' wiring cabling from the incoming/outgoing network junction to the slave(s)? RS-485 isolators repeaters can 'boost' the 485 signal and isolate all devices from excess common mode. But isolators won't solve basic networking issues like excess stub length or misplaced terminating resistors. |
Last edited by: danw at: 11/25/2021 18:02:07Last edited by: danw at: 11/25/2021 18:07:08 |
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