SiriusMark
Member
Hey everyone, I'm just looking for some input on the the network architecture when dealing with DH485 through the 1747-AIC Link Couplers.
First, the equipment:
Cabinet 1: 1 SLC 5/03, 1 AB DTAM, 1 Link Coupler
Cabinet 2: 1 SLC 5/03, 1 AB DTAM, 1 Panelview 1000, 2 Link Couplers
Cabinet 3: 1 SLC 5/03, 1 AB DTAM, 1 link coupler.
As you can probably guess, the link couplers are all connected via the 6 pin connector and Belden 9842 cable. The peripherals are then connected via 1747-C10, except for the processors which were connected via 1747-C11.
In cabinet 2, the original configuration as I walked into the situation was that the first link coupler was connected to the SLC 500 via J1, and then to the second link coupler via J2. The second link coupler was powered via an external 24V power supply, connected to the Link coupler chain via 6 pin connector, and then connected to the Panelview 1000 via it's own J2. The panelview was then daisy-chained to the DTAM unit through it's secondary DH485 port.
Now, this is apparently how it has always been connected, so that method seemed to work. When I arrived, everything had already fried. That was a separate issue related to bad grounding and an electrical surge probably caused by lightning. However, once we got all of those issues fixed and new components installed, I was unable to get the equipment in the second cabinet to function properly. What I finally decided to do was to remove that second link coupler from the equation entirely. I removed it, then ran the cable from the 1st link coupler straight to the Panelview. We didn't have a new DTAM available, so currently that part of the link is not connected. But here's my question. If the DH485 communications is being passed between the link couplers via the 6 pin connector, then why would anyone connect two link couplers together via the peripheral jacks AND the 485 interface jacks? Wouldn't that create some kind of loop? More importantly, wouldn't that create the possibility of bypassing the 1500v isolation that is built into the coupler?
Isn't it wrong, in other words?
First, the equipment:
Cabinet 1: 1 SLC 5/03, 1 AB DTAM, 1 Link Coupler
Cabinet 2: 1 SLC 5/03, 1 AB DTAM, 1 Panelview 1000, 2 Link Couplers
Cabinet 3: 1 SLC 5/03, 1 AB DTAM, 1 link coupler.
As you can probably guess, the link couplers are all connected via the 6 pin connector and Belden 9842 cable. The peripherals are then connected via 1747-C10, except for the processors which were connected via 1747-C11.
In cabinet 2, the original configuration as I walked into the situation was that the first link coupler was connected to the SLC 500 via J1, and then to the second link coupler via J2. The second link coupler was powered via an external 24V power supply, connected to the Link coupler chain via 6 pin connector, and then connected to the Panelview 1000 via it's own J2. The panelview was then daisy-chained to the DTAM unit through it's secondary DH485 port.
Now, this is apparently how it has always been connected, so that method seemed to work. When I arrived, everything had already fried. That was a separate issue related to bad grounding and an electrical surge probably caused by lightning. However, once we got all of those issues fixed and new components installed, I was unable to get the equipment in the second cabinet to function properly. What I finally decided to do was to remove that second link coupler from the equation entirely. I removed it, then ran the cable from the 1st link coupler straight to the Panelview. We didn't have a new DTAM available, so currently that part of the link is not connected. But here's my question. If the DH485 communications is being passed between the link couplers via the 6 pin connector, then why would anyone connect two link couplers together via the peripheral jacks AND the 485 interface jacks? Wouldn't that create some kind of loop? More importantly, wouldn't that create the possibility of bypassing the 1500v isolation that is built into the coupler?
Isn't it wrong, in other words?
