SRT 2200 Switch OFF with delay by Modbus command problem

[Anonymous user]

I have to switch OFF SRT 2200 Smart UPS by Modbus RS-232 command with delay ab out 90sec.

If I write (0x06 command) to Modbus register 1540 (SimpleSignalingCommand_BF) value 0x1 -

APC switch OFF after correct delay time (about 90sec),  but  then immediately switch ON because the input Inlet power is present.

If I write to register 1540 value 0x2 -

APC switch OFF immediately without useful 90sec delay and do not switch on again.

If I  write to register 1538 (0x602 OutletCommand_BF ) value 0x84 or 0x04  -

I reseive an error Modbus reply , seems to  "Slave device or server Failure".

The sending sequence of bytes in (HEX):

01 06 06 02 00 04 29 41

and reply sequence is:

01 86 04 43 A3

So how to Switch OFF SRT 2200 Smart UPS by Modbus RS-232 command with 90sec delay and without switching ON it next moment if input Inlet power is present?

Thank you.