4
Introduction
SC3015
– Thirty-Two-Channel Single Ended Digital Input Card
The SC3015/ Thirty-Two Channel Single Ended Digital Input Card provides two sinking
voltage options. The SC3015/00 is used with 120 VDC digital inputs. The SC3015/02
card is used with 48 VDC digital inputs. Immunity to noise is enhanced with a single pole
low pass filter. Further filtering (e.g. removing contact bounce effects of relays) can be
performed in software using the Bool Hold Open Hold Closed (HOHC) object.
Analog to digital conversion is performed by a 16-bit switched capacitor successive
approximation A/D converter. A precision voltage source provides a self-test function for
the card’s amplifiers and A/D converter and can be used to verify accuracy in user
application logic. No field adjustments are necessary after the initial factory setup.
I/O bus checking diagnostics, card address tests, and configuration tests are performed
each time the controller accesses the card. All data and control transfers are performed
twice, once using the actual data and then using the inverted data. Both versions of the
data are compared to verify that all I/O bus data bits are functioning properly. The
configuration code from the card is compared to the I/O configuration to check that the
correct card is installed in the rack. I/O Bus slot address and control signal contention
tests also are performed. Any fault detected sets status bits in an error detection variable
returned to the user application program.
An indicator LED, located near the top of the front panel, indicates the overall health
status of the card. If this LED is on, the card is functioning normally; if it is off, the card
has detected an error or is offline. If this LED is on, but the card is shown in red on the
SC3015
