[Imported] QP and QH "Hot Standby" model RF Port Variants
>>Message imported from previous forum - Category:Trio Data Radios<< User: joelw, originally posted: 2018-10-17 22:39:29 Id:121 This is a re-posting from the obsoleted (October 2018) "Schneider Electric Telemetry & SCADA" forum.
**_jweder:_** The datasheets do have a fair bit of information, but unfortunately they leave out the context. Take a look at page 8 of the QP and QH datasheets. (copies attached) That page shows the hardware variants. The descriptions in the datasheets and the Reference Configurator are not the easiest to understand, so here is some clarification...
**QH450:** A QH contains two QB full duplex radios and a Hot Standby Controller (HSC), in a 3 RU (rack-unit) stack. Requires two frequencies approximately 5 MHz apart. This allows the QH to transmit and receive at the same time. This provides the ability to operate as a Collision Avoidance Master, maximizing the available bandwidth by reducing collisions to a minimum. The QH has redundant QB full duplex radios for Hot Standby capability. Also included are heat sinks and fans, allowing the active QB to transmit as much as 100% of the time without overheating.
**"A" code** (Separate Tx/Rx Ports) The Tx and Rx ports of both QB's are routed thru the HSC (hot standby controller) which switches one pair of ports (from one radio or the other) to the antenna (and duplexer) based on which of the two is currently active. The description "separate Tx/Rx ports" refers to the fact that the HSC provides separate Tx and Rx ports (one of each) to connect to the duplexer/antenna system.
**"B" code** (Duplicated RF Ports) The Tx and Rx ports of both QB's are NOT routed thru the HSC but instead go directly to two separate duplexers and two separate antennas. The "A" version of the QH is typically used to save a little money, and some space on a tower, by only requiring the use of one duplexer and one antenna. However this leaves both of these items, plus the coaxial cables, as single points of failure. That's why the "B" version exists - for customers who have a bit more money and want to duplicate everything top to bottom. There is one real benefit of having two separate antennas. Typically one of them (used as the preferred repeater most likely) would be mounted higher on the tower while the other would be lower down. That one would have a bit less of a coverage pattern because it can't hear quite as far, but ont he other hand it is far less likely to be struck by lightning and damaged, so is in a great spot to act as a backup radio.
**QP450**: A QP contains two QR half duplex radios and an integral controller, all within a single 1 RU 19" housing. This allows the ability to only transmit or receive. However the QP does provide a large heat sink and fans to allow it to transmit at very high duty cycle. (up to 100% while a QR must be limited to 20% transmit time) The second internal radio and controller provide redundancy, as with the QH.
**"B" code** (Duplicated RF Ports) This option is similar to the "B" code in the QH450. There is one Tx/Rx port for radio 1 in the QP housing, and another Tx/Rx port for radio 2. With two runs of coaxial cables, two surge arrestors and two antennas (likely at different heights on the tower) this provides very good lightning protection. Note however that only one of the two radios is ever in use at any time. (chosen by the internal controller)
**"D" code** (Separate Tx & Rx Ports) Note that this configuration option, shown on the "V0003" QP datasheet, is NOT available in the Reference Configurator. I'm not sure it ever will be.
**"E" code** (Common Tx/Rx Port) The two QR's contained in the 19" rack-mount chassis share a single antenna connector, using an internal RF switch. This is the lower cost option and, like the QH with the "A" code, presents the customer with a single point of failure in the antenna and coaxial cable. (no duplexer used with QP's as they are not full duplex) But it is quite sufficient for many customers, as antennas and cables are the hardware least likely to fail.