West Control Solutions Pro-EC44 - Manual (Page 82)

Pro-EC44 2-Loop Graphical Profile Controller & Recorder
Pro-EC44 Product Manual - 59540-1 October 2013 Page 75
10 Digital Inputs
Digital inputs are driven to one of two states (active or inactive) by an applied voltage signal
or a contact opening/closing.
A total of 9 physical digital inputs are possible on this instrument. A multiple digital input can
be installed at time of purchase, and a single plug-in module can be fitted in option slot A.
Digital Signal Type
The digital inputs can be connected to volt-free contacts, or to a voltage signal (compatible
with TTL). They can often be used in parallel with equivalent menu selections, where either
can change function status.
Some inputs are level sensitive, while others are edge sensitive requiring a High to Low or
Low to High transition to change functions status. Pre-Tune is always off at power-up (except
if auto pre-tune is enabled), but other edge sensitive functions retain their power off status at
power on. See the tables below for details.
Open contacts (>5000Ώ) or 2 to 24VDC signal = Logic High (logic low if inverted).
Closed contacts (<50
Ώ) or -0.6 to +0.8VDC signal = Logic Low (logic high if inverted).
CAUTION: The response time is ≥0.25 seconds. Signals applied for less
than this time may not register and the function might not change state.
A diagnostic screen assists commissioning and fault
finding by showing the current signal state for all
digital inputs.
Slot A, C1 to C8 & Soft digital input status ( =
Active, Ø = Unavailable)
Profile select bit format (BCD or Binary)
Profile selected (example shown: C1-C3 = 011 = 6)
Inverting Digital Inputs
Digital inputs can be inverted to reverse their
action making
an “on” input behave as off.
Step thorough each input using the R key.
Press U to invert  the highlighted input and D
to un-invert . Hold R down to skip to next
screen accepting the values shown.
Highlighted Input