User manual

Publication 1760-UM001A-EN-P
9-2 Troubleshooting
Possible Situations
When Creating Circuit
Diagrams
Possible Situations when
Creating Circuit Diagrams
Explanation Remedy
Cannot enter contact or relay in
circuit diagram
Pico is in Run mode Select Stop mode
Time switch switches at wrong
times
Incorrect time or time switch
parameters
Check time and
parameters
Cannot select analog comparator
“Ax”
Pico ac versions have no analog
inputs
Use Pico dc for
comparing analog
values
Cannot select time switch
contacts
Pico has no clock “-NC” version does not
have a clock
When using a memory module
Pico will display the message
“PROG INVALID”
Pico memory module contains no
circuit diagram
Change the version of
Pico or change the
circuit diagram in the
memory module
Circuit diagram on the memory
module uses contacts /relays that
Pico does not recognize:
• Do not use “-NC” versions for time
switch functions
• Analog inputs only with
1760-L12BWBxx
Current flow display does not
show modifications to the circuit
connections
Pico is in Stop mode Select Run mode
Operation / connection not performed Check the circuit
diagram and parameter
sets and modify as
required
Relay does not activate coil
Incorrect parameter values / time
• Analog value comparison is
incorrect
• Time value of timing relay is
incorrect
• Function of timing relay is
incorrect
Relay “Q” or “M” does not pick
up
Relay coil has been wired up several
times
Check coil field entries
Input not detected Loose terminal contact Check installation
instructions, check
external wiring
No voltage to switch/button
Broken wire
Pico input is faulty Replace Pico
Relay output “Q” does not
switch and activate the load
Pico in Stop mode Select Run mode
No voltage at relay contact Check installation
instructions, check
external wiring
Pico power supply interrupted
Pico circuit diagram does not activate
relay output
Broken wire
Pico relay is faulty Replace Pico