RLY08 Serial Mode

Serial mode selection
Serial Mode is selected by connecting the Mode pin to ground. The Tx pin is out of the RLY08 and should be connected to Rx on your controller. The Rx pin is into the RLY08 and should be connected to Tx on your controller. These signals are 5v levels, not RS232. Do NOT connect RS232 directly to the module - you will destroy it. Use a MAX232 or equivalent to convert the RS232 levels to 5v.

Communication settings
The Serial mode operates over a link with a baud rate of 9600 bps (no parity, 1 stop bit) and 5v signals, The RLY08 can be found at a factory default address of 1, although this is easily changed to another of eight locations - see Changing the RLY08 Address .

Commands
To send a command to the RLY08, you need to send two bytes. The first is the RLY08's address 1 (default) to 8, and then the actual command itself - see below. The RLY08 will then carry out the command and if applicable send its response. The only exception to this being the "Set relay states" command, it requires an additional required states byte to be sent immediately after the command byte. This will then set all relays to the status of the equivalent bit within the byte, with a high bit powering the relay on and a low bit turning it off.

Command		Action
dec	hex	Action
90	5A	Get software version - transmits a single byte back to the controller containing the software revision
91	5B	Get relay states - transmits a single byte back to the controller, bit high meaning the corresponding relay is powered
92	5C	Set relay states - the next byte sent to the command register will set all relay states, All on = 255 (11111111) All off = 0
100	64	All relays on
101	65	Turn relay 1 on
102	66	Turn relay 2 on
103	67	Turn relay 3 on
104	68	Turn relay 4 on
105	69	Turn relay 5 on
106	6A	Turn relay 6 on
107	6B	Turn relay 7 on
108	6C	Turn relay 8 on
110	6E	All relays off
111	6F	Turn relay 1 off
112	70	Turn relay 2 off
113	71	Turn relay 3 off
114	72	Turn relay 4 off
115	73	Turn relay 5 off
116	74	Turn relay 6 off
117	75	Turn relay 7 off
118	76	Turn relay 8 off
160	A0	1st byte in sequence to change serial address
165	A5	3rd byte in sequence to change serial address
170	AA	2nd byte in sequence to change serial address

Changing the RLY08 Address
To change the address of the RLY08 you must have only one module connected. Write the 3 sequence commands in the correct order followed by the address. For example; to change the address of a RLY08 currently at 1 (the default shipped address) to 5, write the following to address 1; (0xA0, 0xAA, 0xA5, 0x05 ). These commands must be sent in the correct sequence to change the address, additionally, No other command may be issued in the middle of the sequence. The sequence must be sent as four separate commands to the current address of the module. i.e. 0x01, 0xA0 then 0x01, 0xAA, then 0x01, 0xA5 and finally 0x01, 0x05. When done, you should label the module with its new address, however if you do forget, just power it up without sending any commands. The RLY08 will flash its address out on the LED. One long flash followed by a number of shorter flashes indicating its address. The flashing is terminated immediately on sending a command the RLY08.

Take care not to set more than one module to the same address, there will be a bus collision and very unpredictable results.

Address		Long Flash	Short flashes
Decimal	Hex	Long Flash	Short flashes
1	01	1	0
2	02	1	1
3	03	1	2
4	04	1	3
5	05	1	4
6	06	1	5
7	07	1	6
8	08	1	7