BECKHOFF M1400 - Manual (Page 3)

M1400 Parallel Input /Output Beckhoff II/O-System
Date : 26.7.94 Version : 2.0 Page 3 of 16
1. Function Description Hardware
M1400
About the Hardware
The parallel module M1400 is an input / output module used in the II/O system. There are 32
Standard 24 V inputs / outputs, which achieve 4 ports of 8 bit each.
These 4 ports ( D0..D3 ) correspond to the data bytes in the FO transmissions protocol and
according to the way they are to be used, they can be configured as input or output.
Each input / output has an LED, that indicates the current state. Furthermore there are three
LED’s installed used for diagnosis of the II/O fibre optical ring:
LD1 The green ’CYCLE’ LED is switched on by each start bit of a telegram and is
switched off again by the stop bit.
LD2 The red ’ERROR’ LED is switched on after the recognition of a bad telegram (checksum,
frame). After a sequence of three correct telegrams (checksum, frame) were processed it
is switched off again.
LD3 The green LED ’WATCHDOG’ is switched on by a valid writing telegram with matching
address. If no telegram with the properties defined above is recognised for the next
100 ms a special unit of the module switches off all outputs.
In case an error is detected, all outputs are reset.