Spectrum Controls 1771sc-IMI16 - Manual (Page 2)

Important Pre-Installation
Considerations
This module must be used with a 1771 Series B (or later) I/O chassis.
This module contains input filtering to limit the effects of voltage transients
caused by contact bounce and/or radiated electrical noise. This filtering cannot
be turned off. The delay due to filtering is:
• Off to On 11
±
6 ms for AC
3
±
2 ms for DC
• On to Off 29
±
8 ms for AC
30
±
7 ms for DC
This module is designed to operate with input devices such as limit switches,
float switches, selector switches, push-buttons, and proximity switches. A
simplified schematic for this module appears in Figure 1.
Figure 1
Simplified Schematic
The module is shipped in a static-shielded container to guard against electrostatic
discharge damage. Observe the following precautions when handling the module:
CAUTION
ELECTROSTATICALLY SENSITIVE COMPONENTS
Observe the following precautions to guard against electrostatic damage:
¥ Wear an approved wrist strap grounding device, or touch a grounded
object to discharge yourself before handling the module.
¥ Do not touch the gold backplane connector or connector pins.
¥ If available, use a static-free work station.
¥ Keep the module in a static-shielded bag when not in use or during
shipment.
Failure to observe these precautions can degrade performance or damage the
module.
Installation Data
AC/DC (220/240 V) Input Module
Cat. No. 1771sc-IMI16
2
System
Circuitry
(filtering)
Opto
Isolation
Input
Indication
LED
1771
Backplane
56.2 k½
56.2 k½
0.15 µf
250 ½
AC High
or DC Positive
AC Low
or DC Common
!