IDENT-I • IRI-KHD2-4.RX, IRI-KHA6-4.RX
Operating control interface units using the 3964R protocol
Subject to reasonable modifications due to technical advances.
Copyright Fuchs, Printed in Germany
Fuchs Group • Tel.: Germany (06 21) 7 76-0 • USA (330) 4 25 35 55 • Singapore 7 79 90 91 • Internet http://www.pepperl-fuchs.com
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The control system terminates the reception when it receives the character sequence
DLE ETX BCC. It compares the block check character (BCC) received with the built-
in longitudinal parity. If the block check character is correct, and no other receive er-
rors have occurred, the control system transmits DLE. If the BCC is incorrect, NAK is
transmitted to the control interface unit, and a repetition of the process is awaited. The
control system terminates the reception if the data block cannot be received without
error after a (programmable) number of attempts, or if the repeat transmission is not
initiated within the (programmable) block delay time.
8.1.3
Basic structure of all messages
1.) Without Interpreter RK512
2.) With Interpreter RK512, communication involving FETCH messages
host
device
STX
DLE
Command, DLE, ETX, BCC
DLE, STX
DLE
Data, DLE, ETX, BCC
DLE
host
device
STX
DLE
Message head, DLE, ETX, BCC
DLE, STX
DLE
Response message head, data, DLE, ETX, BCC
DLE
