The input module DF20EX is equipped with 8

channels according to NAMUR which are split

into two blocks. There is one frequency input

per block and three control inputs/outputs.

The module features protection class Ex ib

IIC and can be mounted in zone 1 in combination with excom. When connecting the field

devices, observe that all inputs/outputs are at

a common potential. The explosion protection

category of inputs/outputs is Ex ia IIC.

The module can be used as a counter or frequency input module: It is thus suited for pulse

counting of binary input signals or frequency

measurements of binary pulse sequences of

NAMUR sensors.

The counting direction can either be set externally via a control input or internally by setting

a parameter. The maximum frequency of one

block is 4 kHz; with 2 blocks the frequency is

reduced to 2 kHz.

Input and output mode can be adjusted

via the Fieldbus master. Each channel is

equipped with parametrizable wire-break/

short-circuit monitoring.

■ Frequency module for the connection of intrinsically safe sensors (according to NAMUR)