Example: Force Multiple Coils Fc 15; Example: Preset Multiple Register Fc16 - DEUTSCHMANN AUTOMATION UNIGATE MB - MPI Instruction Manual

Implemented protocols in UNIGATE® MB
The 2nd row shows the fieldbus data AFTER the write command.

You can see that the value 00 07 is send as Address in the Modbus request. (As mentioned in
the chapter Universal Modbus Master some Master pull System one as offset.)
This leads to the Byte-Offset for the fieldbus output data => 14. You start counting with the first
process data value with Index NULL.
1F 03 02 ....
| +---- 1. process value
+-------- fieldbus length byte
8.8.1.5

Example: Force multiple coils FC 15

Note: The address can only be passed in multiples of 8 incl. Null.
Also 0, 8, 16, ... (Here you also have to keep in mind the offset of 1)

Example: Start address = 0001.
Adr 0002 ... 004 was changed from Low to High
The 1st row shows the fieldbus BEFORE the request:
1F 00 FF 03 04 05 06 07 FF 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00...

1F 0E FF 03 04 05 06 07 FF 12 05 12 06 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00...
2nd row AFTER the request.
Therefor the 1. process data value changed from 00h to 0Eh.
8.8.1.6 Example: Preset multiple register FC16
Only the content of the register address 0005 and 0006 was changed.
30 UNIGATE
®
fieldbus gateway UNIGATE
Deutschmann Automation GmbH & Co. KG
®
MB - MPI V. 1.9 27.10.21