1756-IB16IFK ControlLogix analog input module Supports three (3) types of signal wiring configurations

The Allen-Bradley 1756-IF16 is a ControlLogix analog input module. The module accepts current and voltage signals such as ±10V, 0-10V, 0-5V and 0-20 mA. The module supports three (3) types of signal wiring configurations, such as single-ended, differential, and high-speed differential wiring. Of the supported wiring configurations, single-ended wiring is the most sensitive to noise and must be used with signals with common ground. To improve noise sensitivity, differential wiring methods are used, while high-speed differential wiring is used in systems that require rapid data updates relative to the input signal.

With single-ended wiring, the module becomes a sixteen (16) channel analog input module. Again, when used with differential wiring, the module is reduced to an eight (8) channel analog input module. In addition, when the module is wired as a high-speed differential connection, the module will become a four (4) channel analog input module.

The 1756-IF16 has a single resolution of 320 μV/ count (15-bit + sign bipolar) @ ±10.25V input range; 160 μV/ Count (16 bits) @ 0-10.25V input range; 80 μV/ Count (16-bit) @ 0-5.125V Input range and 0.32μA/ count (16-bit) @ 0-20.5 mA. The scanning time of the module varies, for example, the single-ended scanning time is 16-488 milliseconds; The differential connection is 8-244 ms and the high-speed differential connection is 5-122 ms. It has a built-in analog-to-digital converter circuit using the Sigma-Delta method. The converted data is stored in integer mode (left-justified, 2-second complement) IEEE 32-bit floating-point data format. The module's calibration accuracy is better than 0.05% of the voltage input range and 0.15% of the current input range.

The 1756-IF16 can be wired using three different methods, depending on user and application requirements, such as single-ended wiring, differential wiring, and high-speed mode differential wiring. The single-ended wiring method is best when all input devices are connected to common ground. This is to compare the side of the signal input with the signal grounding to get the difference, which the module then uses to generate digital data for the controller. Differential wiring methods are recommended when applications have no common ground or may have separate signal pairs. This wiring method is also suitable for environments where noise resistance needs to be improved. Channels in differential mode are not completely isolated from each other. If multiple differential input signals have different voltage common references, one channel may affect the reading of the other. When this happens, the user should connect the input to a different module or replace the non-isolated module with an isolated input module. Eight connections are allowed in this mode. Finally, the high-speed mode differential wiring method allows for the fastest possible data update. However, users need to meet certain conditions to use high-speed mode. First, it uses the differential wiring method. Second, in this mode, only one out of every four channels on the module can be used. The 1756-IF16 module consumes 2.3 Watts, and its total backplane power is 2.33 Watts. Input range ± 10 volts, 0 to 10 volts, 0 to 5 volts, or 0 to 20 mA.