Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 901B-2555-A |
| Manufacturer | Control Technology Inc. (CTI) |
| Product Type | 16-Channel Differential Analog Input Module |
| Compatible Platforms | CTI 2500 Series, SIMATIC 505 I/O Base |
| Input Channels | 16 differential |
| Signal Range (Unipolar) | 0–5 VDC, 0–10 VDC, 0–20 mA |
| Signal Range (Bipolar) | ±5 VDC, ±10 VDC, ±20 mA |
| Resolution (Unipolar) | 14 bits + sign |
| Resolution (Bipolar) | 13 bits + sign |
| Update Time (No Filtering) | 5.9 ms |
| Update Time (Filtering) | 8.2 ms |
| Accuracy (Voltage @ 25°C) | 0.057% of full scale |
| Accuracy (Current @ 25°C) | 0.2% of full scale |
| Repeatability | 0.008% |
| Common Mode Rejection | >86 dB @ 60 Hz |
| Channel-to-Backplane Isolation | 1500 VDC |
| Input Overrange Protection | 500 V |
| Backplane Power Consumption | 5.0 W |
| Operating Temperature | 0°C to 60°C |
| Agency Approvals | UL, UL-C, FM (Class I, Div 2) |
Main Features and Advantages
High-density differential input design: The 901B-2555-A delivers 16 differential analog input channels in a single-wide module, dramatically reducing rack space and per-point cost compared to multi-module alternatives. Differential inputs provide 140 VRMS channel-to-channel common mode rejection, effectively suppressing noise from VFDs, motors, and other industrial interference sources that would corrupt single-ended measurements.
Fast update time for responsive control: The 901B-2555-A completes a full 16-channel scan in 5.9 ms without filtering, rising to 8.2 ms with filtering enabled. This speed supports tight PID control loops and fast-responding processes where delayed data would degrade control quality. An 80 ms filter time constant is available for noisy signal environments.
Robust isolation and protection: The 901B-2555-A incorporates 1500 VDC isolation between field channels and the PLC backplane, safeguarding sensitive control electronics from field wiring surges, ground loops, and transient faults. The module also features 500 V input overrange protection, providing defense against accidental wiring errors or voltage spikes that could otherwise damage input circuitry.
Microprocessor self-diagnostics: The 901B-2555-A continuously verifies its operational health and supports Immediate I/O functionality, providing real-time data to the controller without waiting for a full scan cycle. This diagnostic capability reduces troubleshooting time and supports predictive maintenance strategies.
