Deif ASC Series - Modbus master; Modbus protocol and write type; Verification of the communication

DEIF A/S
Page 17 of 26
ASC commissioning guide 4189341077 UK
Modbus master
Using the communication interface requires the use of Modbus master for the Sunspec supported inverters or
inverters with proprietary protocols.
Terminal
Function
Associated menus
29
Modbus communication
A
7561, PV Comm type (for example
Sunspec)
7570, action at PV Communication error
(Modbus master)
7510 Ext comm ID and Baud rate
7520, action at communication error
(Modbus slave)
31
Modbus communication
B
Note that the Modbus line should be properly terminated. Long lines typically with 120 Ohm in each. For short
lines, it is often seen that the termination can be removed.
Note that the Modbus ID in the inverter can be set to the same as in the ASC. The baud rate has to be the
same in the ASC and the inverter.
Modbus protocol and write type
The Modbus transmit specifics is set in menu 7560:
• 7561, select the inverter type.
• 7562, select broadcast or unicast
o Broadcast at multiple string inverters
o Unicast at single string inverters or central inverters
• 7563, transmit rate, set it to 1-2 seconds. Don’t set it below 1 second unless advised to.
• 7564, transmit telegram, use 0x06h prior to 0x10h. Switch to 0x10h if 0x06h is not responding
Verification of the communication
Notice that is is often convenient to start with the communication adjusted to “UNICAST” even though
broadcast is eventually going to be used.
Inverter number
Inverter Modbus ID
Baud rate selected
DEIF ASC comm. ID
1
10
19200
Menu 7511
2
11
19200
Menu 7511
3
12
19200
Menu 7511
Now switch to unicast and adjust the DEIF ASC to a proper ID:
Inverter number
Inverter Modbus ID
Baud rate selected
DEIF ASC comm. ID
1
10
19200
10
2
11
19200
-
3
12
19200
-