DH+ speed using DHRIO

Hi everyone,

I have look in the AB manual but I haven't found the answer to my question.

Does the Allen-Bradley DHRIO module can bridge between a 57.6Kbps network and a 115Kbps network ?

It seems obvious for me that the answer is yes, but before shutting down the network to do the changes, I would like to have some inputs

thanks

pheel

I don't have the manual in hand, but I am thinking you would need two DHRIO's. I think when you select the high speed you only get one channel out of a DHRIO. I am sure some can verify this.

If I wanted to know, I would read the manual. But that's just me.

RSL

RSL said:

I don't have the manual in hand, but I am thinking you would need two DHRIO's. I think when you select the high speed you only get one channel out of a DHRIO. I am sure some can verify this.

If I wanted to know, I would read the manual. But that's just me.

RSL

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well, I'll have a look again in the manual. I even talked to Rockwell this morning and they were not sure. They told me to try and see but I might need a second module.

RSL, I too read the manual when I need information but sometime it's not clear and forum are a nice place to look for people that have already had the experience with the situation.


pheel

I've never actually seen a DH+ network running at 115.4 kb/s. It's a valid selection, and I've run RIO networks at that speed, but usually I only see low speed (57.6 kb/s) and high speed (230.4 kb/s) DH+ networks.

The 1756-DHRIO module added support for 115.2 kb/s dual-channel operation and 230.4 kb/s single channel operation in the Series C hardware, firmware version 5.03. See Rockwell Knowledgebase document G53455026 for the switch settings.

The 1756-DHRIO does disable the second channel if 230.4 kb/s is selected as the DH+ speed. This is only a valid selection for Series C and D of the module hardware.

Is the idea that you were planning to increase the speed of one of your DH+ networks to 115.2 from 57.6 ?

Ken Roach said:

Is the idea that you were planning to increase the speed of one of your DH+ networks to 115.2 from 57.6 ?

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Yes, my customer have 2 57.6 DH+ linked with a DHRIO. They have some problems with one of the 2 networks. Rockwell will be there this friday to do a complete analysis of the situation.

I'm planning to propose a speed increase of their networks. I was thinking of modifying one network at a time. That is why I was asking if one DHRIO module could bridge between a 57.6 and 115.2.

I'm aware of the limitation of high speed 230k that disable the second channel on the DHRIO but I haven't seen anything about mixing speed...