A-B 1746-HSCE High-Speed Counter Module

High-Speed Counter Module Overview

The High-Speed Counter Module, Catalog Number 1746-HSCE is an SLC 500 family 

compatible device except with the 1747-ASB Remote I/O Adapter Module. It can be 

used with SLC™ 5/02 (and above) processors.

The module’s bidirectional counting ability allows it to detect movement in either 

direction. In addition, x2 and x4 counting modes are provided to fully use the 

capabilities of high-resolution quadrature encoders.

High-speed inputs from quadrature encoders and various high-speed switches are 

supported. Accepting input pulse frequencies of up to 50k Hz allows precise 

control of fast motions.

In addition, an Accumulated Counter, the module provides a Rate Counter to 

determine Rate Measurement by indicating the pulse input frequency in Hz. (See 

the block diagram on page 6.) The Rate Measurement is determined by 

accumulating input pulses over a fixed period of time. You set the Rate Period to 

best match your application requirements.

Background Rate calculation is provided in Sequencer and Range Modes. This 

operation accepts input rates up to 32,767 Hz. The dynamically configurable Rate 

Period ranges from 10 ms to 2.55 seconds. 

The module’s four current sink (open collector) outputs can be controlled in the 

user program or the module.

Control of the counter reset is configured through user-set parameters. The counter 

can be reset from any combination of the Z input, Limit Switch input, or Soft Reset control bits.

Module operation is determined by selections made in the Setup and Control Word 

(M0:e.1). Setting the Function Control bit to 1 triggers the module to start the 

proper pulse counter, rate measurement, and output control functions. Many 

parameters are dynamic and can be changed without disrupting counter operation. 

The module’s block diagram is shown on page 6. Inputs from the terminal block 

enter the diagram at the left, outputs to the terminal block exit at the right. M0 and 

Output file parameters from the SLC enter the logic blocks from the top. Input file 

data to the SLC exit the logic blocks from the bottom.

Two dip switches (SW1 and SW2) and one jumper (JW1) are located on the side of  the module. 

• SW1 selects the type of input (single ended or differential). 

• SW2 selects the output voltage range (4.5 to 10V dc or 10 to 30V dc). 

• JW1 selects the filtering rate (300 µs or 10 ms) used to debounce the limit  switch input.

Install the Module 

Installation procedures for this module are the same as for any other discrete I/O or  specialty module.

ATTENTION

Disconnect power before attempting to install, remove, or wire  the module. 

Make sure your SLC power supply has adequate reserve current  capacity. The module requires 320 mA at 5V dc.

1. Align the full-size circuit board with the chassis card guide. 

The first slot of the first chassis is reserved for the CPU.

2. Slide the module into the chassis until the top and bottom latches are 

latched. 

Make sure the removable terminal wiring block is attached to the module 

and all wires are connected to the terminal block.

3. Insert the cable tie in the slots and secure the cable.

4. Cover all unused slots with the Card Slot Filler, Catalog Number 1746-N2.

Important Wiring Considerations

Use the following guidelines when planning the system wiring for the module:

• Install the SLC 500 system in a NEMA-rated enclosure.

• Disconnect power to the SLC processor and the module before wiring.

• Make sure the SLC 500 system is properly grounded. 

• Group this module and low-voltage DC modules away from AC I/O or 

high-voltage DC modules. 

• Shielded cable is required for high-speed input signals A, B, and Z. We 

recommend Belden 9503 or equivalent for lengths up to 305 m (1000 ft).

• When the LS input is driven by an electromechanical device, route the 

wiring away from other inputs. In addition, JW1 should be set for the 10 ms filter. 

• When the LS input is driven by a solid-state device, use a shielded cable. 

You do not have to route the cable away from other inputs. 

• Shields should be grounded only at the end of the signal source end of the 

cable. Ground the shield to the case of the signal source, so energy coupled 

to the shield will not be delivered to signal source’s electronics.