Data Hwy slowing down

[DanWard]

Gerry, here are the facts. networking 101
DH486 max 46 nodes.
DH+ max of 72 nodes @57.6k up to 10,000ft
remote i/o scanner 10,000ft
device net1600ft
control net 18.6 miles fiber/10,000ft cable
ethernet 10 mbps 32 bit ip address unlimited nodes

 

[jstolaruk]

Gerry, here are the facts. networking 101
DH486 max 46 nodes.
DH+ max of 72 nodes @57.6k up to 10,000ft
remote i/o scanner 10,000ft
device net1600ft
control net 18.6 miles fiber/10,000ft cable
ethernet 10 mbps 32 bit ip address unlimited nodes

I'm not familiar with DH486. IIRC the DH485 protocol can handle 31 nodes; mollasses slow I bet.

 

[rPraveenkum]

DH+ max of 72 nodes @57.6k up to 10,000ft

DH+ 77(octal) & 64(decimal)Max nodes


http://www.controlnet.org

 

[OZEE]

Those are theoretical max nodes. Nobody in their right mind would intentionally have more than 15-20 nodes (depending on amount and type of traffic). When you go beyond that, performance starts dropping off rapidly.

 

[Ron Beaufort]

Greetings DanWard ...



and welcome to the forum ...



you said:

DH+ max of 72 nodes

please put us out of our misery and tell us where you’re getting this information ... most of us here think that there are only 64 available node addresses available on DH+ ... we’re having a hard time understanding how we would go about addressing up to 72 nodes ...


here's a handy way to visualize the layout ...

my best guess from here: you’ve got a “book” with a mistake in it ... that happens from time-to-time ... if you don’t mind, please tell us what publication you’re using ... noting those types of errors is a little hobby of mine ...

thanks ...

 

[DanWard]

I got this from a rockwell student package CCP170 for DeviceNet and RSNetworx Design and configuration

 

[DanWard]

my network goes ethernet with 25 devices to a two channel DH+, channel A has 17 nodes and channel B has 9 nodes and a bridge to DH485 with 3 nodes on it. doing a load of messaging and never had performance trouble

 

[Gerry]

Gerry, here are the facts. networking 101
DH486 max 46 nodes.
DH+ max of 72 nodes @57.6k up to 10,000ft
remote i/o scanner 10,000ft
device net1600ft
control net 18.6 miles fiber/10,000ft cable
ethernet 10 mbps 32 bit ip address unlimited nodes

You need to check your facts

 

[Ken Roach]

How embarassing, Dan; that quote from the RSNetworx class is inaccurate in almost every line. Please disregard it.

 

[DanWard]

Ken, then please correct my posting???? I sure dont want to learn to wrong way to network....

 

[Ken Roach]

Some RA networking vital statistics

DH485 max 31 nodes, 4000 ft. trunk.

DH+ max of 64 nodes, 57.6kb/s up to 10,000 ft, 230.4 kb/s up to 2500 ft.

Remote I/O nodes vary by scanner. Same length/speed limits as DH+.

DeviceNet max 64 nodes. Trunkline distance 1640 ft at 125 kb/s, 820 ft at 250 kb/s, 328 ft at 500 kb/s.

ControlNet up to 99 nodes per network, up to 48 nodes per segment, up to 3280 feet (1000 meters) per co-axial segment. Fiber-optic and co-axial repeaters can increase distance.

Ethernet 10/100/1000 Mbps, 32 bit IP addresses, darn near unlimited nodes.

 

[Ken Roach]

Original poster

If I were working on a slow-performance DH+ network I would go after it with all guns blazing: Controller port statistics, RSLinx driver statistics, oscilloscope examination of waveforms, and Frontline Test Equipment FTS4SCADA analysis software.

I have greatly improved some DH+ networks using nothing but controller port statistics and an oscilloscope to repair and tune the physical system. Mostly we found short-circuits to the shield or hanging-by-a-strand wire connections.

When you're dealing with HMI's and unknown amounts of messaging, an analyzer like Frontline Test Equipment's FTE4Control is the only way to go. Because analyzers are so expensive and the knowledge to use them is pretty arcane, I would stronly recommend getting an RA network service engineer to do the work. Then follow him around.

 

[tom_stalcup]

my network goes ethernet with 25 devices to a two channel DH+, channel A has 17 nodes and channel B has 9 nodes and a bridge to DH485 with 3 nodes on it. doing a load of messaging and never had performance trouble

Typically, (as almost everyone has said), no matter what THE BOOKS SAY, a DH+ network will not handle more than 15-20 active nodes. And, depending on the network, 20 can be pushing it.

Your network, with channel B 9 dh+ nodes(good), and channel A 17 dh+ nodes(also good, but pushing it) should be fine. I would recommend(STRONGLY) that you not add any more nodes onto Channel A in the future.... The fact that you are not experiencing communication issues on it is the exception rather than the rule.