configuring the MODBUS plug-in is a bit tricky. The reason: there are
some devices out there that work with wrong
byte order (according to MODBUS specification) and some that use wrong address offsets
(and some that do both
wrong). So when you configure a plug-in for your device you in most cases will not have
exact specification of this
devices behaviour, so you only can try all variants: invert/non-invert address/data
byteorder, start with an address
counting from 0/1.
I’ll go along with that but it appears as if un-checking the box gives small-endian byte
order, and checking it gives big-endien. The box is checked by default so I suppose it
makes a sort of sense.
In version 3.3.2 the return value appeared to be in the wrong order as well though, I had
to divide by 256 to correct it.
Version 3.6 doesn’t appear to receive at all, So far I’ve tried effectively the same
device program but on two different microcontrollers, and a example device program that
outputs a continuous count value on register 999.
A raw com-port dumper would be really useful at this point.
Incidentally the “DLL hell” issue is that if you uninstall OpenAPC 3.6 and reinstall 3.3.2
then you get an odd error and it won’t run. Windows XP and 7. It means I can’t readily
switch between them unless I do something messy like putting OpenAPC in a virtual machine.
I’ve got the error message saved somewhere, can’t find it now. At work I managed to roll
the system back enough to clear it but this home machine’s had 3.6 on too long, system
restore would muck up too many other things.