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Troubleshooting
36 312785C
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
bent inward.
Although unlikely, check the commu-
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
tags on the display.
Delete tags one after another and
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.