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ASM 421 Technical Description
6GT2 097-3AH00-0DA2
– 46 –
RD: 03/02
6GT2 002-0DA00
ASM 421 / V.24
Subject to change without notice!
6GT2 002-0DB00
ASM 421 / RS422
6GT2 002-0DC00
ASM 421 / TTY
J31069-D0142-U001-A0-7618
3.5
Telegrams from file handler
In normal operation the user receives only one telegram (acknowledgement) if a command has previously
been sent to the ASM. In two cases however, the ASM becomes active and sends a telegram to the user
asynchronously:
– Start-up message
– Proximity change
3.5.1
Start-up message
Telegram from file handler:
’H’
CC Status ADB
DBN DBL
00
00
0000
0001
0
1
2/3
4
5
6/7
8/9
10
0001
00
00
Note:
After sending a start-up message, the file handler firmware will only accept a RESET telegram.
All other commands will be rejected with an error!
The file handler sends the start-up message whenever power is restored. If the user is not ready to re-
ceive, a number of repeats will be carried out within the framework of the 3964R procedure
(see section 3.1).
If the user receives a start-up message during operation, the 24 V supply has failed for a short period. A
previously programmed command will no longer be processed by the file handler.
3.5.2
Change in proximity status
A change in proximity status (Z message) will only be signalled by the file handler if this has been specified
by setting the DIL switch on the module (see section 2.3).
Telegram from file handler:
’Z’
CC Status ADB
DBN DBL
00
00
0000
0001
0
1
2/3
4
5
6/7
8/9
10
0001
05
00
11/12/13/14
15
Error code
ANW
Proximity status of an MDS:
’0’
= No MDS present; the MDS has just moved out of the
transmission window
’1’
= MDS present; an MDS has moved into the transmission
window of the SLG. (green LED on ASM is lit)
EXCEPTION: If the “connection to SLG” has been broken
since proximity (ANW) is reported in this
way. As a result when the user sends his
command to the ASM, he receives the
corresponding error message in the
acknowledgement).
No error code is given for a proximity message (ASCII: ’0000’)
Important:
The proximity change message comes fully asynchronously from the ASM. The user must always
be ready and able to accomodate this message.