Parker Products OEM350X, OEM650X manual Daisy Chaining, Daisy Chain Configuration

INSTALLATION • OEM650/OEM650X

Daisy Chaining

You may daisy chain up to 8 OEM650Xs. Individual drive addresses are set with signals 23, 24, and 25 on the 25-pin D connector. When daisy chained, the units may be addressed individually or simulta- neously. You should establish a unique device address for each OEM650X. Refer to Figure 2-20 for OEM650X daisy chain wiring.

Rx	OEM	Tx	OEM	Tx	OEM	Tx
Tx		Rx		Rx		Rx
	s		s		s
Gnd	e	Gnd	e	Gnd	e	Gnd
	r		r		r
	i		i		i
	e		e		e
	s		s		s
	POWER		POWER		POWER
	FAULT		FAULT		FAULT
	REMOTE		REMOTE		REMOTE
	REF		REF		REF
	CURRENT		CURRENT		CURRENT
	DUMP		DUMP		DUMP
	VDC+		VDC+		VDC+
	VDC-		VDC-		VDC-
	A+		A+		A+
	A-		A-		A-
	B+		B+		B+
	B-		B-		B-

Figure 2-20. Daisy Chain Configuration

Commands prefixed with a device address control only the unit specified. Commands without a device address control all units on the daisy chain. The general rule is: Any command that causes the drive to transmit information from the RS-232C port (such as a status or report command), must be prefixed with a device address. This prevents daisy chained units from all transmitting at the same time.

Attach device identifiers to the front of the command. The Go (G) command instructs all units on the daisy chain to go, while 1G tells only unit #1 to go.

When you use a single communications port to control more than one OEM650X, all units in a daisy chain receive and echo the same commands. Each device executes these commands, unless this command is preceded with an address that differs from the units on the daisy chain. This becomes critical if you instruct any indexer to transmit information. To prevent all of the units on the line from responding to a command, you must precede the command with the device address of the designated unit. No OEM650X executes a device-specific command unless the unit number specified with the command matches the OEM650's unit number. Device-specific commands include both buffered and immediate commands.

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