Watlow Series SD31 PID with Optional Countdown Timer - Manual (Page 62)

Wa t l o w S e r i e s S D 3 1
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6 0
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C h a p t e r 1 0 F e a t u r e s
Indication Probable Cause(s) Corrective Action
No power.
Controller appears dead.
No display indication in either
window.
Power to unit may be off.
Fuse may be blown.
Breaker may be tripped.
Safety interlock door switch, etc. may be acti-
vated.
Separate system limit control may be latched.
Wiring may be open.
Input power may be incorrect.
Check switches, fuses, breakers, interlocks,
limit devices, connectors, etc. for energized
condition and proper connection.
Measure power upstream for required level.
Verify supply power requirements using the
part number.
Check wire size.
Check for bad connections.
Set point value not displayed Display Default [~dsp] (Setup) is not set to
[`Set]. Press ß key to access set point.
Verify that [~dSP] is at the desired setting.
Process value not displayed Display Default [~dsp] (Setup) is not set to
[proc]. Press ß key to access process val-
ue.
Verify that [~dSP] is at the desired setting.
Cannot establish serial data com-
munications with the controller. Address parameter may be incorrectly set.
Baud rate parameter may be incorrectly set.
Unit-to-unit daisy chain may be disconnected.
Communications wiring may be reversed,
shorted or open.
EIA-485 converter box may be incorrectly
wired.
Computer’s COM port may be incorrectly set
up.
Communications software setup or address
may be incorrect.
PC software’s protocol or parity may be wrong.
Parity should be 8, n, 1.
Application software is not working properly.
May need termination, pull-up and pull-down
resistors.
Check Setup Page and set to correct address.
Check Setup Page and set to correct baud
rate.
Look for a break in the daisy chain.
Verify correct connections and test wiring
paths.
Check converter box wiring and its documen-
tation.
Reconfigure computer’s COM port setup and
verify that communications are ok.
Check the communication card documentation
for settable variables and operational testing.
Restart PC software and check for settings
agreement. Verify the COM bus is active.
Verify operation with Watlow communications
tool available at www.watlow.com.
Add termination resistors for EIA/TIA-485
(see Install and Wire chapter).
Output signal is on when it
should not be. Output wiring is incorrect. Verify the output wiring.
Output parameters are set incorrectly. Verify the output parameter settings.
DC voltage applied to output option “K” (solid-
state relay output). Solid-state relay option can be used with al-
ternating current (ac) voltage only.
Output signal is not on when it
should be. Output wiring is incorrect. Verify the output wiring.
For solid-state relay (option “K”) and mechani-
cal relay (option “E” or “J”), power must be ap-
plied. Verify that power is applied to the output. The
output simply acts as a switch.
Output parameters are set incorrectly. Verify the output parameter settings.
Troubleshooting