Controlling SG Ready modes on S series

[bj00rn]

Trying to implement control of SG ready state on my S1256.

Has anyone achieved this using modbus?

From what i can tell all the SG Ready registers are read only:

nibe/nibe/data/s1155_s1255.csv

Line 748 in 34e94d8

SG ready, input A MODBUS_INPUT_REGISTER 1912 1 4 0 0 0

nibe/nibe/data/s1155_s1255.csv

Line 749 in 34e94d8

SG ready, input B MODBUS_INPUT_REGISTER 1913 1 4 0 0 0

nibe/nibe/data/s1155_s1255.csv

Line 747 in 34e94d8

Operating mode (SG Ready) MODBUS_INPUT_REGISTER 1911 1 4 0 0 0

[bj00rn]

@BartThoen do you have any input on this 🙏 ?

[BartThoen]

You cannot do it over modbus, you have to do it with an external contact. You need to configure the AUX outputs as input A and input B and then you need a relay to switch them.

[bj00rn]

I think it should be possible using the AUX from modbus feature, unless I am reading the docs wrong. Rather quirky solution though, sad that A/B registers are not writable.

[bj00rn]

Example SG Ready 1:1 - Ordered

1. Set A register
   • send 20 to 2470 (42471)
   • send 1 to 2471 (42472)
2. Set B register
   • send 21 to 2470 (42471)
   • send 1 to 2471 (42472)

[bj00rn]

Seems to work! I can't see any indication on the heatpump display that SG ready is active