CTI 2502 - High-speed Counter Encoder Module

Product Summary

The CTI 2502 Two-Channel High Speed Counter Input Module is a member of Control

Technology’s family of I/O modules compatible with CTI 2500 Series™ and Simatic® 505

programmable controllers. It is designed to count pulses on the inputs and return the

current count and status to the controller.

Features

The 2502 provides two independent high-speed counter channels. Each channel includes

the following features.

 Four counter modes:

 Pulse counter

 Quadrature counter modes: 1X, 2X, 4X

 A 10 kHz count rate with a minimum pulse width of 25 s.

 Four inputs:

 two count inputs

 reset

 inhibit

 Two field outputs, each controlled by a separate programmable preset.

 LED indicators display the status of the A and B count inputs, and of Y1 and Y2

outputs.

 All inputs may be sinking or sourcing (with external 24 VDC power supply).

Front Panel Description

Active LED

The Active LED will be illuminated when the module is functioning normally. If the Active

LED is not lit, or if it is blinking, refer to Chapter 3 for troubleshooting.

Asynchronous Operation

The module operates asynchronously with respect to the PLC.   The controller is

programmed to monitor and control the operation of the High Speed Counter module using

the words and bits provided in the module interface.  The module provides reset, inhibit,

output, and counter status in three WX input words.  The controller uses 5 WY output words

to control counting, control outputs, and set counter presets.

Inputs

The 2502 Two-Channel High Speed Counter Module has two independent counting

channels.  Each channel has four inputs. Each input may be used as either sinking or

sourcing (with external 5–24 VDC power supply). The input signals are connected to the

field wiring terminal block.

Reset - Current flow through the reset input sets the channel’s counter to

zero. The counter will be held at zero until the reset input becomes

inactive.

Inhibit - Current flow through the inhibit input inhibits the channel from

counting. The counter holds at the last value and does not change until the

inhibit input becomes inactive.

Counter Input A, Counter Input B - The relationship of the states of these two inputs,

combined with the counter mode setting, determines the direction of the count. Typical

devices for counting are high-speed static switches or incremental encoders.