Hello everyone,
I am lookimg for some help to figure out where come from the problem or what i can do to improve the latency.
PLC:
S7 416-5h redundant system
PLC is connected via Profinet to the AOS server.
this AOS is connected to different PLC all are updated value around 2-4s
but one PLC, the one who have more Items 15 000 items. Values are updated every 10s !
Archestra config :
Our vendor config, 10 Topics with interval like this
TOP01 1001 ms interval update
TOP02 1002 ms interval
TOP03 10003 ms
and so on
when I use wireshark to see what's happen, I found
that 1 request is send to PLC then after 10ms another is send,
then PLC is answer to the 1st request after 110ms then a new request is send it to PLC. all the cycle took 10s the DA server is only sending two request at the time until he got a answer to the 1st one then send a new one.
i try to understand the cause,
- why only 2 request ? is there a parameters I can set to send send more then 2 at the time.
-110ms is it fast enough for get the answer from PLC (HMI is also connect so it can slower the com)
-The interval update time setting are strange to me, doesn't it ?
- the AOS is sending 183 request to the PLC, PDU are 480 bytes in some doc they are talking that S-400 can go to 960 bytes ? any idea ? i might reduce the messages by larger PDU.
- do you know which is the best option for Cyclic Services
•Disable S7 cyclic service
• Maximum available
• Limit cyclic services to
might change something
than you in advance for your help
I am lookimg for some help to figure out where come from the problem or what i can do to improve the latency.
PLC:
S7 416-5h redundant system
PLC is connected via Profinet to the AOS server.
this AOS is connected to different PLC all are updated value around 2-4s
but one PLC, the one who have more Items 15 000 items. Values are updated every 10s !
Archestra config :
Our vendor config, 10 Topics with interval like this
TOP01 1001 ms interval update
TOP02 1002 ms interval
TOP03 10003 ms
and so on
when I use wireshark to see what's happen, I found
that 1 request is send to PLC then after 10ms another is send,
then PLC is answer to the 1st request after 110ms then a new request is send it to PLC. all the cycle took 10s the DA server is only sending two request at the time until he got a answer to the 1st one then send a new one.
i try to understand the cause,
- why only 2 request ? is there a parameters I can set to send send more then 2 at the time.
-110ms is it fast enough for get the answer from PLC (HMI is also connect so it can slower the com)
-The interval update time setting are strange to me, doesn't it ?
- the AOS is sending 183 request to the PLC, PDU are 480 bytes in some doc they are talking that S-400 can go to 960 bytes ? any idea ? i might reduce the messages by larger PDU.
- do you know which is the best option for Cyclic Services
•Disable S7 cyclic service
• Maximum available
• Limit cyclic services to
might change something
than you in advance for your help