Command String, On Command, Decimal, Hex

The Command String

All Command Strings consist of four ASCII characters. The first character is the start of message character, "X-off" (decimal 19). The second and third characters represent the hexadecimal address of an individual 485DSS. The address range is from 0 to 255 (HEX "00" to "FF"). Some commands require the use of the broadcast character "DC2" (decimal 18) as the second and third characters in the command. The fourth character is the command character.

Command Syntax: X-off	____	____ ____

			Command character.
		Least signf. address character.
	Most signf. address character.

Start of message character.

ON Command

This command turns on an individual 485DSS and asserts the RTS output handshake line on pin 4 of the DB25 connector. This command allows the RS-232 device connected to the 485DSS to access the RS-485 network. The address field in the command string specifies which 485DSS is to turn on. All other 485DSS's on the network will turn off if the address field does not match their address setting.

Command character: SOH (decimal 1)

Example 1: To turn on the 485DSS set to address 15 decimal (0F hex).

HOST transmits: Xoff “0” “F” SOH

( 19 48 70 1 decimal) ( 13 30 46 1 hex)

Example 2: To turn on the 485DSS set to address 33 decimal (21 hex).

HOST transmits: Xoff	“2”	“1”	SOH
( 19	50	49	1 decimal)
( 13	32	31	1 hex)

10485DSS-0308 Manual

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