Siemens PXC-16 Compact Technical Reference Manual page 96

Service Information
Troubleshooting the TX-I/O Island Bus
Symbol
Incorrect point The point type displayed does not correspond to
type the point type defined in the database.
Display is OFF Insufficient DC power.
or
also check
Display is ON, but
TX-I/O Power Supply LED (
communications
are failed
Field device supply (
also check
The field device supply LED on the TX-I/O
Power Supply (24V~) or Bus Connection Module
( ) are bright green.
Point is configured as an output signal and no
field device supply is available.
Invalid process value (current output)
No sensor (current input)
Value above range limit
96 | 100
Siemens Industry, Inc.
Building Technologies
LCD Panel Indications.
Status Indicator
) is bright green.
) is missing or very low.
Technical Reference Manual
Restricted
Check
Using the job drawing or field panel layout sheet, verify
that the address keys are in the correct module.
Ensure CS and are connected to the Bus
Connection Module (BCM).
Ensure CS/ at the BCM is within 0.5 Vdc of CS/
at the Power Supply.
– The wire length may have attenuated the DC
power.
– Ensure the module diagnostics report is
normal.
● Is a TX-I/O module connected to the wrong side of
the Power Supply or Bus Connection Module?
The TX-I/O island bus must extend from the male
bus connector of the Power Supply or Bus
Connection Module.
● Is the field device supply LED OFF? If so:
– The 4A replaceable fuse may be blown.
– The field device supply may be off.
– Wires may be disconnected.
● Is the field device supply LED dimly lit?
– The field device supply may be too low.
● Is a TX-I/O module connected to the wrong side of
the Power Supply or Bus Connection Module?
The TX-I/O island bus must extend from the male
bus connector of the Power Supply or Bus
Connection Module.
● Is the field device supply LED OFF? If so:
– The 4A replaceable fuse may be blown.
– The field device supply may be off.
– Wires may be disconnected.
● Is the field device supply LED dimly lit?
– The field device supply may be too low.
● Ensure the output current loop is intact.
● The ? symbol has higher priority than the !
symbol.
● Ensure the sensor power wire is landed on the
sensor power terminals of an 8X module (3, 11,
20, or 28) and not on field device supply terminals
(7, 15, 24, or 32) of 8U or 8X modules.
● Verify the external wire at the sensor.
● An internal sensor wire may have a break.
● NTC resistance is too low (temperature over
range).
● RTD resistance is too high (temperature over
range).
● The voltage or current input is too high.
145-172
2018-09-25