EUCHNER AS-i 3.0 Command Interface - Manual (Page 19)

AS-i 3.0 Command Interface Commands of the Command Interface
Subject to reasonable modifications due to technical advances Id.-No.: 102875 Issue date - 3.12.2007 EUCHNER GmbH + Co. KG
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4.2.5 RD_74_DIAG
With this function the diagnosis string of a slave according to profile S-7.4 is being
read. Since the string can be longer than the command interface, it is written into
the buffer. The content of the buffer can be read in parts from index i.
The first byte of the buffer indicates the length of the read string.
If i
≡ 0, the string is being read from the slave, otherwise the function responses
out of the memory, the data can be read consistently.
4.3 Acyclic commands
4.3.1 Overview of the commands
4.3.2 WRITE_ACYCLIC_TRANS
This function starts various types of acyclic transfer (S-7.4, S-7.5 and Safety Mon-
itor). The transfer is performed in the background. The result must be read using
READ_ACYC_TRANS. The function is intended to be a replacement for the func-
tions (RD_74_75_PARAM, WR_74_75_PARAM, RD_74_75_ID, RD_74_DIAG
and "Safety at Work" monitor diagnostics), as it runs in the background and does
not stop the AS-i master during the transfer.
As the data to be transferred can be longer than the command interface, the data
is first written to a buffer in sections before the transfer is started.
Request
byte
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1 5D
16
2 T – circuit
3 slave address
4 i
Response
byte
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1 5D
16
2 T result
3 buffer byte i
… …
n+2 buffer byte i+n-1
Values for command
see page Command Value Meaning
Req
Len Res
Len
page 19 WRITE_ACYC_TRANS 4E
16 write acyclic transfer ≥7 2
page 21 READ_ACYC_TRANS 4F
16
read acyclic transfer 5 ≥2