Watlow PPC-2000 - Manual (Page 177)

PPC-2000 User’s Guide Chapter 4: Troubleshooting
Doc.# 30002-00 Rev 2.3 Watlow Anafaze 151
PPC-2040 Digital I/O
Refer to the following descriptions of LED indicators when
troubleshooting the digital I/O module.
• Green Status LED remains off, on, or blinks
incorrectly: When the module is correctly functioning the
green LED blinks. If the LED remains off, on, or blinks
incorrectly, the module may not be functioning correctly.
Corrective Actions:
Make sure the rotary switch is set to the proper module ad-
dress. Each module must have a unique address.
Cycle power to PPC-2000 system.
Check that the modules are connected properly; refer to
Module Assembly on page 24.
Perform a RAM clear; refer to Resetting Closed-Loop
Control Parameters on page 156.
Replace the module.
• Green Status LED is blinking but inputs and/or
outputs are not reading correctly:
Corrective Actions:
Check to make sure the I/O wiring is correct. See Con-
necting I/O to the PPC-2040 on page 61.
• Red Error LED remains on: Indicates at least one
digital output is in an incorrect state. The cause could be
an overloaded output or a failed output driver.
Corrective Actions:
Check the output circuits for shorts and repair if nec-
essary.
Check the load on the outputs to make sure that none of
them exceeds 150mA.
Check to make sure the I/O wiring is correct. See Con-
necting I/O to the PPC-2040 on page 61.