Functional description
5
gas-lab
Q1
Page 93
Error
number
S5/S7 error
name
Cause of the error
00H
------------
OK telegram after SEND
0CH
memory
access
-
A DB has been addressed which does not correspond
with the DB of an RK512 job.
-
The first addressed data word is not within the data
area of the addressed DB.
-
The addressed data is longer than the addressed DB.
10H
instruction 2
The second instruction letter is wrong. Here, only 'D' is
permitted to stand for DB.
11H
access not
permitted
A telegram with data has been sent, but no access rights for
its DB/DW area exist.
16H
instruction 1
The first instruction letter is wrong. Only 'A' for SEND and 'E'
for FETCH are admissible.
34H
telegram
length
-
The telegram that arrived was incomplete (not enough
data).
-
The length stated in the SEND telegram and the length
of the telegram itself do not correspond.
5.6.2.3
Protocol-specific facts: MODBUS RTU / MODBUS ASCII
The Modbus protocol is supported, for instance, by the PLC series of AEG
Modicon. The data presentation according to the Modbus protocol is one-
dimensional. The smallest data unit in the memory consists of 16 bits. The
protocol contains a number of registers that are numbered consecutively from 0
up and each of which may contain exactly such a 16-bit word. In each individual
case the number of registers depends on the size of the memory available on
the host side.
The positions of the import and export values of the host are indicated as serial
register numbers in the parameterisation of the
gas-net
device, too. These
register details always refer to the MODBUS telegram presentation. This may
possibly lead to different register numbers in the PLC, depending on the host
type.