26.9.2013
56
AS-i 3.0 PROFIBUS Gateway in Stainless Steel
PROFIBUS DP
10.2 DP/V1
To exchange data between the PROFIBUS master and the AS-i/PROFIBUS gate-
way via PROFIBUS DP/V1 only one data block is used - slot 1, index 16. Within
this data block a command interface is installed like the one used in the DP tele-
gram.
The DP/V1-command interfaces are edited every time they are sent. Therefore it
is possible to execute the same command several times without changing "com-
mand" or "circuit" and setting a toggle bit.
10.3 Restrictions
The SPC3 has only 1,5 KByte DP-RAM available. Therefore the lengths of tele-
grams and the numbers of DP/V1-connections to class 2 masters have to be re-
stricted.
Information!
I+M service contains data for identification and maintenance. This service is on by
default. Switching the services off provides additional memory into SPC3. This
changes the DP/VD length-limit.
Restrictions due to the SPC3
MSC1 inputs data / outputs
data
single master: 288 bytes
1
doppel master: 272 bytes
2
diagnosis 62 bytes
parameter single master: 53 bytes
doppel master: 88 bytes
configuration
3
32 bytes
SetSlaveAddress 4 bytes
MSAC1 SAPs
PDU
1
72 bytes
4
MSAC2 SAPs
PDU
2
72 bytes
5
Tab. 10-28.
1. The maximum length of the input and output data can vary up to 288 bytes input or output data if
the I+M (information+maintenance) service is on only. The maximum length of the input and output
data (both master) is not variable and it is limited to 144 bytes (for input and output data) if the I+M
service is disabled.
2. The maximum length of the input and output data can vary up to 272 bytes input or output data if
the I+M (information+maintenance) service is on only. The maximum length of the input and output
data (both master) is not variable and it is limited to 144 bytes (for input and output data) if the I+M
service is disabled.
3. Maximally 8 modules can be configurated
4. The maximum length is limited to 42 bytes if the I+M service is set to off.
5. The maximum length is limited to 52 bytes if the I+M service is set to off.