Host Engineering Forum
General Category => Do-more CPUs and Do-more Designer Software => Topic started by: Controls Guy on August 08, 2022, 04:34:12 PM
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I set up some Modbus/TCP remote I/O with the I/O scanner, and want to map 96 outputs starting from Y32 to the remote I/O. If I'm configured for raw copy, DMD won't let me enter Y32:SD or SW or UW as the data source. In single register mode I can, but then I only get Y32-Y47 sent to the remote. DMD says that the data source isn't signed/unsigned WORD/DWORD, which all those casts definitely are, so I don't know why the scanner config won't accept them.
Obviously I can break it up into multiple writes, write to an acceptable buffer first, or just use an MWX (which does work), but seems like it would be a lot cleaner if I can just pipe the Y's directly to the scanner. Is there a way?
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If it's multi-coil read/write FC, just enter Y32. That's a bit FC, not a register FC, so the # of bits does not have to be byte/word/dword aligned, nor be multiples of 8/16/32 (unless the remote device has limitations on this, which some do). It should handle 96 bits.
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If it's multi-coil read/write FC, just enter Y32. That's a bit FC, not a register FC, so the # of bits does not have to be byte/word/dword aligned, nor be multiples of 8/16/32 (unless the remote device has limitations on this, which some do). It should handle 96 bits.
Yeah, but it's not a coil write. The starting register for the outputs is 412289.
Update: OK, there's a 0xxxx register range that hits the same outputs, and if you use that and just use Y32 as the source, all is good! Thanks!
Is there a reason casts of Yxx can't be the source for register writes?
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Duped it - we can look at it.
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I have a standard application involving two BRX, one MWXing and MRXing to the other. Is there any advantage (other than reads continuing) to convert that to MBS scanner comms?