FSR IT-R4S - Manual (Page 7)

7
IT- R4S Operation
The IT-R4S is an ASCII controlled serial input Relay Module that functions very similar to the
IT-R4 Switch Relay Module but differs in the way in which the operation of the relays are
controlled. Control is accomplished through the use of an RS-232 interface using standard ASCII
protocol. The four relays, which are designated as Relays “1, 2, 3 & 4”, can be configured
through the use of serial input commands generated by a host terminal using standard ASCII
format.
NOTE: The Baud Rate for the IT-R4S Serial Port COM1 is fixed at 38,400. IT-R4S Serial
Port COM2 pass-through can be change as shown under “Serial 2-Baud Rate Request”.
Serial Protocol
The protocol for the IT-R4S is a pure ASCII protocol. It can handle the relays individually or in
combinations. An ASCII space character “ ” is used between fields in the request except for the
function, which is immediately followed by a carriage return (, 0x0D).
Relay Function Request:
The user will be able to send the IT-R4S relay functions to perform. The functions can
be on individual, multiple, or all relays.
“R” Function
Relay numbers
Where:
“R”
Relay Request.
Function the type of function to perform on the relays
“O” = Open, Turns relay(s) off.
“C” = Closed, Turns relay(s) on.
“T” = Toggle, Flips status of relay.
“P” = Pulse for ¼ second.
Relay numbers
relays affected by this request
“1”, “2”, “3”, “4” Individual Relay
“,” Multiple relays, 1,2,3 would be relays 1,2,3
“A” is all relays
Note: the comma and dash do not get spaces between them or the relays they delimitate.
Examples:
“R C 1” Turns on relay 1.
“R T 1,3” Toggles the status of relays 1 and 3.
The IT-R4S will respond with a status message that reflects the relay’s status after performing
the relay message (see below).
Relay Status Request:
The user will also be able to check the status of relays, by sending Relay Status Request.