Allen-Bradley 1771-IFM PLC-5 Fast Millivolt Analog Input Module
Configured for high-speed analog voltage processing in Allen-Bradley PLC-5 systems, the Allen-Bradley 1771-IFM, also cataloged as the 1771-IFM Fast Millivolt Input Module, provides direct physical/electrical execution across 8 isolated signal channels. The unit accepts low-level differential millivolt signals, converting field voltage data directly to 16-bit binary numeric format for real-time backplane transfer. It operates with a current draw of 0.75 A at 5 VDC directly from the 1771 I/O chassis backplane logic bus, bypassing the need for external module logic power supplies.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 1771-IFM |
| Brand | Allen-Bradley |
| Origin | USA |
| Weight | 1.30 lbs (0.59 kg) |
| Dimensions | 11.5 in x 4.5 in x 2.0 in (29.2 cm x 11.4 cm x 5.1 cm) |
| Operating Temp | 0 to 60 deg C (32 to 140 deg F) |
| Power Consumption | 0.75 A @ 5 VDC (Backplane) |
| Input Channels | 8 differential inputs |
| Signal Input Ranges | 0 to 50 mV, 0 to 100 mV, -50 to +50 mV, -100 to +100 mV DC |
| Backplane Bus Compatibility | Allen-Bradley 1771 I/O Chassis (PLC-5 System) |
Backplane Bus Communication & Deterministic Processing
The Allen-Bradley 1771-IFM integrates directly with the PLC-5 backplane bus, utilizing high-speed parallel transfer to maintain deterministic I/O scan timing across all 8 input channels. Firmware flash compatibility and backplane timing synchronization allow the module to perform analog-to-digital conversions with minimum scan latencies. Digital filtering algorithms within the module onboard processing circuit attenuate high-frequency industrial field noise while ensuring high channel density scaling across standard 1771 I/O chassis slots. Channel data is presented to the processor block transfer structure, mitigating backplane signal degradation across multi-rack topologies.
Frequently Asked Questions
Q: What is the primary source of operational power for the 1771-IFM input card?
A: The module draws its operational logic power directly from the 1771 I/O chassis backplane bus at 0.75 A at 5 VDC. Field signals require separate proper isolation, but no external secondary power supply is required for module backplane operation.
Q: How does channel-to-channel noise impact millivolt signal acquisition on this unit?
A: The module utilizes differential signal routing for each of its 8 channels to minimize common-mode noise interference. To maintain signal integrity at low millivolt levels, field wiring must use individually shielded twisted-pair cables with proper single-point shield grounding.
Field Installation Guidelines
- Power Isolation: Ensure main chassis power is turned off before inserting or removing the 1771-IFM module from the 1771 I/O rack. Hot-swapping without removing chassis power may cause unexpected system faults or transient backplane disturbance.
- Keying Pin Placement: Insert the plastic keying bands into the chassis backplane connector corresponding to positions between pins 10/12 and pins 24/26 to prevent incorrect module insertion into standard I/O slots.
- Wiring & Shielding: Connect field millivolt conductors using high-grade shielded twisted-pair cable. Terminate signal shields exclusively at the designated wiring arm chassis ground terminal or single-point system ground bar. Do not ground both ends of the cable shield to prevent ground loops.
- Arming & Latching: Secure the field wiring arm (1771-WA) onto the module front housing. Ensure the swing-arm mechanical latch locks securely onto the upper and lower chassis rails to resist industrial vibration.
Allen-Bradley 1771-IFM PLC-5 Fast Millivolt Analog Input Module
Allen-Bradley 1771-IFM PLC-5 Fast Millivolt Analog Input Module
Configured for high-speed analog voltage processing in Allen-Bradley PLC-5 systems, the Allen-Bradley 1771-IFM, also cataloged as the 1771-IFM Fast Millivolt Input Module, provides direct physical/electrical execution across 8 isolated signal channels. The unit accepts low-level differential millivolt signals, converting field voltage data directly to 16-bit binary numeric format for real-time backplane transfer. It operates with a current draw of 0.75 A at 5 VDC directly from the 1771 I/O chassis backplane logic bus, bypassing the need for external module logic power supplies.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 1771-IFM |
| Brand | Allen-Bradley |
| Origin | USA |
| Weight | 1.30 lbs (0.59 kg) |
| Dimensions | 11.5 in x 4.5 in x 2.0 in (29.2 cm x 11.4 cm x 5.1 cm) |
| Operating Temp | 0 to 60 deg C (32 to 140 deg F) |
| Power Consumption | 0.75 A @ 5 VDC (Backplane) |
| Input Channels | 8 differential inputs |
| Signal Input Ranges | 0 to 50 mV, 0 to 100 mV, -50 to +50 mV, -100 to +100 mV DC |
| Backplane Bus Compatibility | Allen-Bradley 1771 I/O Chassis (PLC-5 System) |
Backplane Bus Communication & Deterministic Processing
The Allen-Bradley 1771-IFM integrates directly with the PLC-5 backplane bus, utilizing high-speed parallel transfer to maintain deterministic I/O scan timing across all 8 input channels. Firmware flash compatibility and backplane timing synchronization allow the module to perform analog-to-digital conversions with minimum scan latencies. Digital filtering algorithms within the module onboard processing circuit attenuate high-frequency industrial field noise while ensuring high channel density scaling across standard 1771 I/O chassis slots. Channel data is presented to the processor block transfer structure, mitigating backplane signal degradation across multi-rack topologies.
Frequently Asked Questions
Q: What is the primary source of operational power for the 1771-IFM input card?
A: The module draws its operational logic power directly from the 1771 I/O chassis backplane bus at 0.75 A at 5 VDC. Field signals require separate proper isolation, but no external secondary power supply is required for module backplane operation.
Q: How does channel-to-channel noise impact millivolt signal acquisition on this unit?
A: The module utilizes differential signal routing for each of its 8 channels to minimize common-mode noise interference. To maintain signal integrity at low millivolt levels, field wiring must use individually shielded twisted-pair cables with proper single-point shield grounding.
Field Installation Guidelines
- Power Isolation: Ensure main chassis power is turned off before inserting or removing the 1771-IFM module from the 1771 I/O rack. Hot-swapping without removing chassis power may cause unexpected system faults or transient backplane disturbance.
- Keying Pin Placement: Insert the plastic keying bands into the chassis backplane connector corresponding to positions between pins 10/12 and pins 24/26 to prevent incorrect module insertion into standard I/O slots.
- Wiring & Shielding: Connect field millivolt conductors using high-grade shielded twisted-pair cable. Terminate signal shields exclusively at the designated wiring arm chassis ground terminal or single-point system ground bar. Do not ground both ends of the cable shield to prevent ground loops.
- Arming & Latching: Secure the field wiring arm (1771-WA) onto the module front housing. Ensure the swing-arm mechanical latch locks securely onto the upper and lower chassis rails to resist industrial vibration.
