The Allen-Bradley 1746-ITB16 is a SLC500 fast response discrete input module. This module is installed to an SLC 500 chassis and compatible for use with any of SLC 500 processors. This module is designed with Sixteen (16) input channels, designed to receive high-speed inputs or those that operates at a rapid switching frequency. Though compatible with any SLC controllers, when the 1746-ITB16 is used with SLC 5/03 or SLC 5/04, the processor and the discrete input interrupt (DII) instructions with 100 µsec polling, up to 1kHz of frequency pulse can be read. If signals originate from a gray code encoder, pulse frequency can reach up to 2 kHz. When used with a gray code encoder, recommended Allen-Bradley device is 845D Absolute Gray Code Encoder.

The 1746-ITB16’s operating voltage is 10-30VDC with nominal voltage of 24VDC. It supports sink wiring configuration and has a backplane current draw of 0.085 A at 5VDC. Each channel of the module has a maximum signal delay of 0.43 ms for OFF to ON transition and 0.5 ms for ON to OFF transition while the maximum OFF state voltage is 5VDC and maximum OFF state current is 1.5 mA. The module’s nominal input current is 8 mA at 24VDC.

This module occupies a single slot of the of the 1746 chassis and directly attached to the chassis backplane. This module does not support removal under power (RIUP) thus, install this module only when power is removed from the chassis.

This module requires a backplane current of 0.85 A at 5V DC. It has a maximum signal delay of 0.3 ms at On-state and 0.5 ms at Off-state. It has maximum Off-state current and voltage of 1.5 mA and 5V DC respectively. The 1746-ITB16 has a nominal input current of 8 mA at 24V DC and maximum power dissipation of 3.6 W. With its rapid operation, it is suitable for time-critical applications. The 1746-ITB16 is responsible for receiving and storing analog data in a digital format in its data image table for retrieval by all modular and fixed SLC 500 processors. It supports connections from up to eight separate sensors or actuators for various applications. Its removable terminal blocks eliminate the need to disconnect wires, which makes replacement easy. The 1746-ITB16 also has filter circuitry and optical coupling for reducing signal noise. The 1746-ITB16 module input values can be accessed by SLC 500 processors using Ladder Logic programming. Troubleshooting becomes easier with the LED indicators that show the module’s input status values. The 1746-ITB16 uses a sharing-based hardware platform which includes various combinations of digital and analog I/O. This saves cost and space. The 1746-ITB16 is intended for operation in an environment with a temperature of 32 - 140 °F and a noncondensing relative humidity of 5-95%.