In the December 2013 installment I was lamenting the fact that Burk IP-8 panels for the Burk ARC-16 are no longer available, and I suggested a method to roll your own equivalent. I have an example to share.
To roll your own, simply convert the open collector outputs from the ARC-16 to relay outputs as an example. Dennis Sloatman, my boss here in Los Angeles, came up with a great way to do this. Automation Direct makes panels with 16 relays that can be mounted to a rack panel via DIN rails, and pressed in to service easily enough. It works great in place of the relay portion of the IP8 panels. Best of all, the cost is only about $133. Automation Direct also sells a cable that gets you from the panel connector to a pigtail; just solder the pigtail connections to the DB-37.
There is one very import caveat that you need to be aware of before you deploy any ersatz IP-8. If you are an ARC-16 user you know that the relay outputs do not close for any other reason except being commanded to do so by the front panel buttons, the ESI, or via AutoPilot. This is also true when applying power to the unit. If you use an outboard relay panel, be absolutely sure that there are no unexpected relay closures from your panel when either power-cycling the ARC-16, or your panel itself. Try all the combinations.
Figure 1 shows an array of three 2RU rack panels (constructed by my colleague Jerry Burnham). The top and bottom rack panels are each holding one of the Automation Direct ZL-RRL16-24-1 panels. The middle rack panel has a relay that is energized by the ARC16's 11V output (that formerly went to an IP-8 panel) and it supplies 24Vdc to the relay panels; therefore, this relay must be energized (from the ARC-16) before power is applied to either of the relay output panels. This is our protection against unexpected relay chattering on either of the 16-relay panels.
Irwin is RF engineer/project manager for Clear Channel Los Angeles. Contact him at firstname.lastname@example.org.