Catalogue → Allen-Bradley → ControlLogix 1756 redundancy
1756-RM2XT
Allen-Bradley · Communications module · ControlLogix 1756 redundancy confirmed
| Manufacturer | Allen-Bradley (also Rockwell Automation, AB) |
|---|---|
| Family | ControlLogix 1756 redundancy |
| Category | Communications module |
| Without separators | 1756RM2XT |
| Notes | Redundancy module, extended temperature; verified: Rockwell 1756-sg001 ControlLogix Selection Guide |
What changes what this is worth
Same catalogue number, different money. These are the attributes that separate two otherwise identical 1756-RM2XT units — check each one before you quote or bid.
Series letter
Series letter on the label. Later series are not always backward compatible and sell for more.
Printed on the label, usually right after the catalogue number, as "SER A".
Firmware revision
Firmware/FRN revision. Buyers match it to an existing project; a mismatch can make the unit useless to them.
On the label as "FRN" or "FW", and on the module's own display if it powers up.
Tested or untested
Tested / as-is / new-in-box. The single biggest multiplier on used price.
Not on the plate. It comes from whoever pulled the unit, and it moves the price more than anything printed.