Gateway 312785C important safety instructions Serial Communication Troubleshooting

Troubleshooting

Serial Communication Troubleshooting

This section is used to troubleshoot the communication between two devices linked via serial ports, i.e. RS232 or RS485.

TIP: For communication troubleshooting, it is strongly advised to create a new Graco Gateway database including only one data tag mapped to a known register in the target device.

PROBLEM	CAUSE	SOLUTION
Values show “----”	Port settings do not match.	Check that the port settings of the
		Graco Gateway device match the tar-
		get device (i.e. Baud, Parity, etc.).
	Incorrect target device address.	Check that the target device address
		in Graco Gateway (in communica-
		tions on the PLC symbol) matches
		the target device address setup.
	Incorrect cable.	Check the cable part number or
		cabling to match your protocol.
	Incorrect communication port.	Check if the cable is connected to the
		correct communication port.
		If the above is correct, check that the
		protocol settings are on the correct
		communication port in Graco Gate-
		way.
	Communication port connector pins	Although unlikely, check the commu-
	bent inward.	nication port connector pins on the
		Graco Gateway in case some are
		bent inward resulting in a bad contact
		with the cable.
	Incorrect tag mapping.	Check that the tag is mapped to an
		existing register in the target device.
Values blink between the data and	Incorrect tag mapping on one of the	Delete tags one after another and
“----”	tags on the display.	download in-between. When the val-
		ues on the screen stop blinking, the
		last deleted tag was mapped incor-
		rectly or accessed an unknown regis-
		ter in the target device.
	Communications times-out.	Increase the Slave Response or
		Device Timeout on the communica-
		tion port or target device in Graco
		Gateway.

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