EX213, 221, 230 & 233
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5.6 The Inputs
The EX221 has 16 lines digital input card with jumper selectable options for nominal 5 or 24 volt input
operation with or without opto-isolation on the inputs.
Opto-isolation
To select opto-isolation on the EX221s inputs set J43 to J58 to OPTO-ISOLATED INPUT MODE as
displayed on the silk-screen. Opto-isolation is selected per bit, any combination of isolated and non-
isolated inputs are allowed.
Volt free contact input
To select a Volt free contact input set J43 to J58 to LOGIC LEVEL INPUT this allows the input to float
up to +5 Volts supplied from VCC. This input can then be pulled to ground by an external contact
closure. This mode can also be used as a buffered TTL level logic input to the 200 series cards.
Low/High Range
The EX221 can operate within the following voltage ranges:
Opto-isolated input mode :
Low Range
J14- J29 Inserted
High Range
J14 – J29 Removed
Input Signal low (‘0’ at PPI input)
-5V to +1.5V
-15V to +2.0V
Input Signal high (‘1’ at PPI input)
+4.0V to +20V
+10V to +50V
Volt free contact input mode :
Input Signal low (‘0’ at PPI input)
-1V to +1.5V
Input Signal high (‘1’ at PPI input)
+2.0V to +5.0V
Low range is selected when jumpers J14 to J29 are fitted, high range is selected when J14 to J29
have been removed.
Low/High range can be individually selected for each bit, and any combination of the two ranges is
allowed.
Light Emitting Diodes D1 – D16 indicate status of the input.
Please note that negative logic applies to the volt free contact inputs.
Jumpers J59- J72
These jumpers connect the 0V inputs together in each group so B0 0V is connected to B1 0V, by
using J66 for ease of wiring.
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