Pilot Communications SPM93 - Read the Relay Output Status (Function Code 01 H)

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Section 9.3.1 will describe the format of Read/ Response Packet of relay output.
Section 9.3.2 will describe the format of Read/ Response Packet of holding register.
Section 9.3.3 will describe the relay control command
Section 9.3.4 will describe Preset Multiple Registers packet and the acknowledge
packet.
9.3.1 Read the Relay Output Status (Function Code 01H)
Use 01 command to read the relay status. Relays are addressed starting at 0: relay 1
is addressed as 0.
The relay status data in response packet is packed as one bit for one relay. 1= ON,
0 = OFF.
The LSB (Least Significant Bit) of the first data byte contains the request addressing
output. Other relay is same as this, until to the high bit of this byte, and rank from low
bit to high bit in the followed byte.
If the return output Num. is not a multiple of 8, it will use zero to fill in the remainder bit
of last data byte (until to the high bit of the byte). The byte count field specifies all byte
num. of the data.
Request Packet
(Master→DFPM93)
Response Packet
(DFPM93→Master)
Unit ID/ Slave
1 byte
Unit ID/ Slave
1 byte