Example: Write Single Register Fc6; Example: Force Multiple Coils Fc 15 - DEUTSCHMANN AUTOMATION UNIGATE MB EtherCAT Instruction Manual

Deutschmann Automation GmbH & Co. KG Implemented protocols in UNIGATE® MB
The internal buffer reserves this value, which means it can be read back by the Master via FC1
Read Coil status:
8.7.1.4

Example: Write Single Register FC6

Modbus Master sends the value 1234H in Address 0008:
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Der Modbus Master sends the request to the UNIGATE :
[01] [06] [00] [07] [12] [34] [35] [7c]
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The UNIGATE sends a response:
[01] [06] [00] [07] [12] [34] [35] [7c]
The 1st row shows the fieldbus data BEFORE the write command:
1F 03 02 03 04 05 06 07 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00... .
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1F 03 02 03 04 05 06 07 00 00 00 00 00 00 00 12 34 00 00 00 00 00 00 00 00 00 00 00 00 00...
The 2nd row shows the fieldbus data AFTER the write command.
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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
8.7.1.5

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)
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Example: Start address = 0001.
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17.7.17 UNIGATE fieldbus gateway UNIGATE MB - EtherCAT V. 1.4 27