How to control multiple relays to output different switch states with one command

2022-03-09 18:11:41| 次| 0次

When one command controls the action of multiple relay output channels:

1. Use to write multiple coil registers function code: 15 function code (hexadecimal: 0f);

2. The relay channel of control output must be continuous without interval;

3. The status of each relay output channel can be set differently.

Instruction (hexadecimal) details:

Specific control instructions:

field	meaning	detailed description
FE	Device address	Hexadecimal, representing hexadecimal 254 broadcast address
0F	0f instruction	Write multiple coil function codes
00 00	Starting address	Starting from the relay of the first circuit, 00 represents the first circuit
00 10	Control quantity	Number of relay channels controlled, 16 channels
2	Byte length	Send command byte length (8 channels are 1 byte)
FF FF(/00 00）	Full open and full close command	Specific control instructions
A6 64（/A7 D4）	CRC16	Check bit

The coil register uses binary 1 and 0 states to represent the output state of the specific relay. Write 1 to represent the on of the relay and write 0 to represent the off of the relay, with one byte per 8 channels.

give an example:

① In the 16 channel relay output command, 1, 3, 5, 8, 10 and 12 are disconnected and others are on. The specific calculation process of control command is as follows:

Binary:

Hexadecimal control instruction: 56 (1-8 channels) AF (9-16 channels)

All control commands are as follows:

FE 0F 00 00 00 10 02 56 AF D8 08

② In the output command of channel 10 relay, 2, 4, 6 and 8 are disconnected and others are on. The specific calculation process of control command is as follows:

Binary: