Answer:
1. There are three hardware platforms available in the K Series. Internally they are very much the same, and they are configured very similarly, but there are differences.
KR900/240 - This radio is built into a strong cast aluminum chassis. It has two serial port connectors. Port A is an RJ45, while Port B is a DE9 type. The System port is separate, and is an RJ45. Port A can be changed between RS-232 and RS-485 via jumper change and configuration change. (this is true of all three radio models) Port B's pin 9 can be switched between RSSI indication, Multi-Master control or GPS Sync. The serial ports are wired in the traditional DCE style, so modem cables must be used to connect to a terminal such as a SCADAPack, PLC or PC.
This radio might be chosen by someone who wishes the sturdiest physical design, who wants a DE9 serial connector, or who wants a radio that can sit in an exposed location without any worries. Also, the MultiMaster Sync feature, allowing two or more Masters to share the same location, is only available in the KR900/240. The RF connectors are TNC type for maximum sturdiness.
KP900/240 - This model is meant to be somewhat less expensive than the KR900/240, and be more easily mounted in a cabinet along with other industrial equipment. It has a simple "clam-shell" type case for mechanical protection, but the case will provide only limited protection against moisture, insects, etc. (the circuit board is coated to provide significant protection, however) Mounting clips are available to snap the radio on to a DIN "top hat style" rail.
Another significant difference is that Port B is on the same RJ45 connector as the System port. This means there's no separate DE9 connector. As a result, Port B is only available as a 3 wire port, and uses non-standard pins. (297488 cable goes from port B to DE9) The RSSI pin has been moved to the power supply connector, and the Multi-Master Sync feature is not available. The RF connectors are SMA type for reduced cost and size.
The KP, KI and KB radios were modified by Control Microsystems to match the previously existing Freewave and MDS radios built in to SCADAPacks. As a result the serial ports are non-standard, wired as DTE. This means you need null modem cables to communicate with terminals such as SCADAPacks, PLC's or PC's. But on the plus side this means you can use a SCADAPack programming cable (297217)!!
KI900/240 - This radio model is only available built in to a SCADAPack. Fuctionally it is virtually the same as the KR900, except that Port B uses an RJ45 connector instead of a DE9. (but is still a fully pinned out connector, similar to the KR900) On a couple of points it matches the KP900. The RSSI pin is on the power supply connector, and Multi-Master Sync is not available. (KR900/240 only)
The KI900/240 will be available in the SP3xx series, SP100, SPLP and SP32 only. (along with any future SCADPack designs) The RF connectors are SMA type for reduced cost and size.
The KB900/240 is functionally exactly the same as the KI900 but is a board-only version. It will be installed in devices such as the SolarPack, and sold as an OEM board to third parties.
2. There are two frequency ranges available: 900 MHz and 2.4 GHz. One range or the other may not be available in certain markets. For example, in Europe only the 2.4 GHz range may be purchased. Sales Support can assist with this. If you have both ranges available, how do you choose between them?
900 MHz - The lower the frequency of operation, the further the signal will be able to travel. This is partly due to the greater ability of a lower frequency to bend as it passes through the atmosphere. Also, 2.4 GHz tends to be absorbed more easily by such things as wet trees and heavy cloud cover. So if you need the signal to travel a significant distance, 900 MHz is the better choice.
2.4 GHz - This band of frequencies may not be as crowded as the 900 band in certain areas. As a result your system may have fewer collisions and thus fewer retries. This means potentially higher data throughput. Also, as mentioned earlier, the 900 MHz band may simply not be available, and so 2.4 GHz is the only choice. (e.g. in most of the world other than the Americas and Australia) 2.4 GHz is often used for the backbone system tying several 900 MHz systems together. Being on a different band allows the radios to exist at the same site with virtually no issues of interference between them.
3. Interface port type. The K Series has two serial ports. The J Series have two ethernet ports for user connections, as well as two serial ports sharing one DE9 connector. But we'll leave discussion of the ethernet radios for another day.