Emerson SLS1508 - DCS Distributed I/O Unit Module

Electronic Marshalling eliminates the need to partition the

I/O wiring to specific channels based on signal type. Simply

connect field signal multi-cores in an orderly fashion as

desired. Install the appropriate CHARM to complete the

field circuit and the signal is ready to be used by any one of

four controllers. No cross-wiring required.

Each CHARM acts as a circuit protection device and field

wiring disconnect. Signals are inherently current-limited

to protect against wiring faults to ground. Each CHARM

provides surge protection to meet industry standards in

the area of EMC. Under extreme overvoltage conditions

due to incorrect field wiring, the CHARM will act as a fuse to

protect adjacent channels. Signal faults are thus isolated to

the single CHARM.

Although any signal type can be installed in any location on

the CHARM baseplates, it is recommended that AC voltage

circuits be separated from low voltage signals to comply

with safety recommendations and to mitigate induced noise

in the signals. Standard Terminal blocks, Fused Injected

Power terminal blocks and Relay Output Blocks can be used

on the same carrier, typically, to allow the use of DO 24V

DC isolated CHARMs on higher wattage and 3-wire devices

alongside of standard 24V DC instrumentation signals or relay contacts.