Data transmission
General
A combination of telegram characters is grouped together for the
transmission of data. The telegrams accept the “Handshake
function”, i.e. each telegram from the computer to the recorder
must be first confirmed before being sent.
Notice
Prior to data transfer the interface address and the baud rate
must be defined.
Telegram characters
(UART characters or Frame)
Every sign (frame) has 11 bits, a startbit (ST) with “logical 0”
signal, 8 information bits with “logical 0” or “1” signal, an optio-
nal parity bit (P) with “logical 0” or “1” signal and a stopbit (SP)
with logical “1” signal.
0
b1
b2
b3
b4
b5
b6
b7
b8
(P)
1
ST
2
0
2
1
2
2
2
3
2
4
2
5
2
6
2
7
(P)
SP
Permissible address
The recorder only answers queries which use the address set in
the unit as target address. Permissible are values between 0
and 126 (= 7E H). These can be allocated in any manner de-
sired. However, no double addresses may be allocated. The re-
corder does not reply to faulty messages (check sum, wrong
address, other faulty reception). Also, faulty messages are not
acknowledged.
Some data ranges are identified as “read only” fields. Attempts
to write into such fields will be ignored by recorder.
Broadcast address
Messages to the broadcast address (133 dec) are processed by
all recorders, no response is however given to a broadcast
message.
Telegram formats, framework specifications
The recorder accepts the following types of telegram:
6
Data transmision
