Table of Contents
Advertisement
AS-Interface Analyser
Fig. 8:
In the data mode the momentary data of the slaves are indicated. The tab "Digital
Data" shows the transferred bits from master call and slave response of all slaves
taken up to communication.
For a correct interpretation here four details to AS-Interface:
• According to the SPS-standard EN 61131 binary output data are transmitted
as "1" for a HIGH-level, as "0" for a LOW-level. That applies to communication
between control and master in the data image of the outputs. According to the
AS-Interface standards IEC 62026-2 and EN 50295 within the AS-Interface net
exactly the opposite applies to the "AS-Interface Level".
Both representations are possible: In the menu it can be given under "Options
/ Statistics" whether the exits are indicated as "AS-Interface level outputs" or
as "Process Image Output". The display of the output data is inverted thereby
so that the comparison with the data of the control or within the net becomes
simpler depending upon the situation.
• With each data call 4 bits between master and slave are exchanged in both di-
rections. That applies, even if they are partly insignificant. Therefore, the analy-
ser shows 4 output bits for example also with a pure input slave. They have,
however, no meaning for the application.
• With analog slaves and safety-related slaves the in- and/or output values
transferred in the net constantly change. That is to be detected in the 1 second-
rhythm and corresponds to the function of AS-Interface. But this does not mean
that an error has been observed.
• With A/B-slaves according to specification C.S.2.1 the output bit A3 of the data
call is not available as a usable output value. It serves for the distinction be-
tween A- and B-slaves. So the output bit O3 of the data call for A/B-slaves ex-
hibits always fixed values. In fig.8 the values for the slaves for 4A and 4B are 1
and/or 0.
Subject to reasonable modifications due to technical advances.
23
SIEMENS AG · Low-Voltage Controls · Phone +49 911 895 59 00 · Fax +49 911 895 59 07 · Internet: http://www.siemens.com/lowvoltage/technical-assistance
Functions of the Analyser
s
Printed in Germany
Advertisement
Table of Contents
