Spectrum Controls 1769sc-IF8u - Manual (Page 68)

58 Compact IO ™ Universal Input module
(EMI), improper grounding, improper wiring connections, and unauthorized
tampering. If you suspect a program has been altered, check it against a
previously saved master program.
Safety Circuits
Circuits installed on the machine for safety reasons, like over-travel limit
switches, stop push buttons, and interlocks, should always be hard-wired to
the master control relay. These devices must be wired in series so that
when any one device opens, the master control relay is de-energized,
thereby removing power to the machine. Never alter these circuits to
defeat their function. Serious injury or machine damage could result.
Module Operation
vs. Channel
Operation
The module performs diagnostic operations at both the module level and
the channel level. Module-level operations include functions such as
power-up, configuration, and communication with a 1769 bus master, such
as a MicroLogix 1500 controller, 1769-ADN DeviceNet Adapter, or
CompactLogix controller.
Channel-level operations describe channel related functions, such as data
conversion and over- or under-range detection.
Internal diagnostics are performed at both levels of operation. When
detected, module error conditions are immediately indicated by the module
status LED. Both module hardware and channel configuration error
conditions are reported to the controller. Channel over-range or under-
range and open-circuit conditions are reported in the module’s input data
table. Module hardware errors are typically reported in the controller’s I/O
status file. Refer to your controller manual for details.
Power-up
Diagnostics
At module power-up, a series of internal diagnostic tests are performed. If
these diagnostic tests are not successfully completed, the module status
LED remains off and a module error is reported to the controller.