Writing to Modbus ASCII Holding Registers

[oldgrey1]

1. When writing to holding registers, does one simply update the Channel from which the

[AzeoTech]

1) I think you are using the old driver here. You should see the type of I/O types you talk about in #2. Just don't use the old driver. On the new driver, you can (at least under RTU) simply set an input channel, meaning if you have read holding register S16, you can do mychannel = 4 and it will set that holding register to 4. Give it a try under ASCII

2) Set Register S16 is the same as write to holding register. You can't write to an input register, so "holding" is assumed. The (6) means use Modbus function 6. S16 is the data type, in this case Signed 16 bit integer.

[oldgrey1]

OK, thanks for that.

Yes, I am using the old driver.

The answers make sense now (I think!) - I will give it a try on the live system.

Yes, it is a Holding Register that I want to update.

Cheers for now.