I need to connect a Universal HSP (SMPI, Upstream) with a SMEMA interfact (downstream). Can anyone give me some information about the SMPI interface? Or does anyone have a schematic of a conversion box from SMPI to SMEMA?
Hi Andreas. The SMPI is a proprietary Universal board transfer protocol. GSM platforms from about 1996 and newer have both SMEMA and SMPI. Although UIC later called it BPP1 (Board Pass Protocol) and BPP2, which is basically SMPI for lane-1 and SMPI for lane-2 in a dual lane environment. Even single lane machines still use BPP1.
They keep the schematics of the conversion boxes pretty close to the hip since it is a propritary protocol. You may be able to find someone out there with used conversion boxes they are no longer using since newer machines don't need them.
Another thing to keep in mind, if the board flow direction was changed from what it was built for in the factory, you may need to swap pins 1&2 with pins 3&4 on the SMEMA side. They also made a pig-tail adapter plug that did the same thing. Good luck.
Andreas, Depending on what model of HSP you have the answer can be different. I'm guessing you may have a 4790 or 4791. If this is the case you may need a SMPI-SMEMA conversion box as you have indicated. Also note that there is a specific "upline cable" and "downline cable" for these models. If you have them swapped, they won't work properly. You may want to verify the following....
Input Side (Left Side) "S1PL" = P/N 43711103 Output Side (Right Side) "S2PL" = P/N 43711203