slow dh+ network

hello again!
i have a dh+ network with 3 slc 5/04, 2 panel views, and 3 pls 5/25.
one of the plc-s have a panel view connected with it .

on one of the 5/04 i have connected a remote I/O rack by means of using a scanner and adapter.

the plc-s and slc-s have almost all communication bits between them.

my problem is that the net is slow and i have erroes 5 and 2 on the pls-s.

also the panel view that is not on the dh+ suppose to activate something on another pls but that does not work always.

some said that the communication bits require a special programming.
can you helm me with that?

Please explain what you mean by "the PLCs and SLCs have almost all communication bits between them." and "I have erroers 5 and 2 on the PLC-5's".

It sounds to me like your network is poorly installed and that MSG instructions in each controller may be incorrectly configured or programmed.

You should post a screenshot of the RSWho browse, as well as answers to those two questions, and provide a description of how data is supposed to be exchanged between controllers on this network.

well you are corect.
the network it is poorly instaled.
all the controler use MSG instructions to comunicate.
and allmost all have been programmed differnt.
i do not have a screen shot but the ESwho looks like this

00 pls 5/25
01 pls 5/25
02 slc 5/04
03 plc 5/25
06 slc 5/04
10 pv550
20 pv1100
75 slc 5/04
76 plc 5/25

the node 00 have communicate with panel view t50 and here i have the problem.

when a command is given on the T50 it does no "arrive" to the node 01.

i hope this will help.
thanks

mariuslaprairie said:

well you are corect.
the network it is poorly instaled.
all the controler use MSG instructions to comunicate.
and allmost all have been programmed differnt.
i do not have a screen shot but the ESwho looks like this

00 pls 5/25
01 pls 5/25
02 slc 5/04
03 plc 5/25
06 slc 5/04
10 pv550
20 pv1100
75 slc 5/04
76 plc 5/25

the node 00 have communicate with panel view t50 and here i have the problem.

when a command is given on the T50 it does no "arrive" to the node 01.

i hope this will help.
thanks

Click to expand...

I am a little confused. Is your HMI communicating with the PLC5 at Node 00, or Node 01? I assume there is a typo, and your HMI is a PV550?

It has always been my understanding that is undesirable to have gaps int he DH+ Station Addresses, as this causes delays while the Token is passed to the missing Nodes, and the system has to wait for the Token Hold Timeout.

I am not sure I would use address 00. as that might be the default address for a new device installed on the system.

Allen Bradley Data Highway information can be found here;

http://literature.rockwellautomatio...itle&SortOrder=Asc&passedLangVal=EN - English

Of course there is always Google as well.

Stu......

hi again,

I WILL HAVE TO MAKE A BIT OF MODIFICATION ABOUT MY CONFIGURATION.
SO:
NODE 00 PLC 5/10 WITH A PANEL VIEW 1200 CONNECTED AS A REMOTE I/O
01 PLC 5/25
02 SLC 5/04
03 PLC 5/25
06 SLC 5/04
07 PV 550
10 PV 1000C
70 RSLINX COMPUTER
75 SLC 5/04
76 PLC 5/25

WHEN A COMMAND IS GIVEN ON THE PV 1200 CONNECTED TO THE NODE 00 A VALVE SHOULD CLOSE ON THE NODE 01
AND THIS IS NOT ALWAYS HAPPENED.

I DO NOT HAVE A RESISTOR AT THE END OF THE NETWORK
ALSO THE NET IS NOT MADE AS A DAISY CHAIN .

ANOTHER QUESTION IS WHERE IN THE NETWORK SHOULD THE COMPUTER STAND?

It sounds like you already understand some of the problems with the network.

A DH+ network running at 57.6 kb/s should have one termination resistor (150 ohms) at each end of the network.

DH+ networks can be installed as a "trunk and drop" configuration with 1770-SC Station Connectors or as a "daisy-chain" configuration. Daisy-chain is the most common.

Ideally, daisy-chain and trunk/drop connections should not be mixed.

"Star" and long-dropline connections are not good.

I would change the RSLinx station to Node 11, and see if you can change the other high-numbered nodes to adjacent nodes. Token-passing to absent nodes is not a critical issue on DH+ but large gaps in node numbering do not help.

If you can post examples of the DH+ messaging logic, then somebody may be able to provide advice.

NODE 00 PLC 5/10 WITH A PANEL VIEW 1200 CONNECTED AS A REMOTE I/O

Click to expand...

And a side note about the above quote, the PLC5/10 does not support RIO protocol. A typo? Your PV just another node on the DH+?

sory,
i had a paper with all the network at work and maybe i mixed up a bit.
so the node oo might be a plc 5/15 or 5/25.
he pv is definetily conected as a RIO.
sounds funny but i am seding this from home.
i do not have acces to the internet at work.