Siemens AS 488 Manuel D’Utilisation

Product Information

November, 2001

AS 488/TM

M02.02

S79220-A0977-A-10-7637

Page 18 of 18

Further information:

The arithmetic accuracy of the AS 488/TM with floating-point numbers is higher than that
of the AS 235. There may therefore be small deviations in the last digits of the mantissa in
the case of calculated analog values or floating-point constants in TML.

The CD coupling is not implemented in the AS 488/TM.
Any attempt to register a CD coupling from OS or AS 235 will be rejected.
Remedy: When importing structures, CD couplings must be replaced by DI couplings
before

Loading a filed structure from AS to AS using the command "LAB,name;" is only possible
from an AS 235 with a diskette drive. Saving from AS to AS on diskette using the
command "ARB,name;" is only possible on an AS 235 with diskette drive. Use of an
AS 488/TM as the central configuring station is not envisaged, i.e. all commands which are
not directed to the own AS like for example the LABR and ARBR commands, are not
allowed from the AS 488/TM and may lead to malfunctions in both AS.

When using the function "Read RAM" by PROGRAF AS+ from an AS 488/TM, the number
of transmit telegrams per cycle in the AS is limited by the parameter settings of FSA,ORPA
in the AS 488/TM (A,FSA,ORPA; F; P,26,10;).

Structuring of I/O modules with STRUK-EA via the system bus (CS 275 or PROFIBUS-
TM) has not been released for AS 488/TM.

S5KS Blocks:
When projecting S5KS blocks, special care must be taken to ensure that these are always
placed in the same cycle for the same module and the same channel. The S5KS blocks
use a joint send buffer for each module and channel. If this send buffer is accessed at the
same time by two cycle levels (for example, by cycle 2 and 3) with the S5KS blocks, the
send data to be transported can occasionally be corrupted or destroyed when it enters the
send buffer; the receiver then receives corrupt data.

Time after network is switched on:
On rare occasions it may be the case that, despite the battery memory, the time on the
AS 488/TM is reset to 01.01.94 / 00:00:00 when turned on.
Correction (offline):
Start a terminal program (e.g. windows terminal or HyperTerminal) on the IBS terminal PC,
which is connected to the serial port COM1.
Settings: 19200 Baud, no parity, 8 data bits, 1 stop bit.
Then call up the BIOS setup (press Q and switch on the CPU).
Set the correct date in the setup menu and save the settings.
After this has been set once, the battery memory will function for the date and the time.