Technical Documentation

Commands
The USB-RLY16 operates with an easy to use command set as described in the table
below. Most commands are only a single byte and if applicable the USB-RLY16 will
automatically send its response. The only exception to this being the "Set relay states"
command which requires and additional desired states byte to be sent immediately after
the command byte.
Command
dec hex
Action
90 5A
Get software version - returns 2 bytes, the first
being the Module ID which is 9, followed by the
software version
91 5B
Get relay states - sends a single byte back to the
controller, bit high meaning the corresponding
relay is powered
92 5C
Set relay states - the next single byte will set all
relays states, All on = 255 (11111111) All off = 0
93 5D
Get DC input voltage - returns relay supply
voltage as byte, 125 being 12.5V DC
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