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Datum Systems PSM-500 Series Programmable SCPC/VSAT Modem

The PSM-500, or "M500S" uses Datum Systems' proprietary techniques of direct modulation and demodulation to completely eliminate transmit and receive IF sections and their associated filters.

Datum Systems' latest satellite modem implementation represents state of the art enhancements to the popular PSM-4900 series of modems at the industry's lowest price. The new PSM-500 series incorporates all of the features of the PSM-4900, and adds 8PSK and 16QAM modulation modes, a standard Reed-Solomon and IBS multiplexer and higher data rates. The multiplexer's overhead channels provides the capability for orderwire, AUPC and Remote Modem Control to every modem. The PSM-500 series is available in IF versions for 70 MHz, I40 MHz and L-Band applications.

To provide capabilities consistent with customer needs, the PSM-500 may be purchased in 3 upgradeable versions or "Feature Sets", the M505, M511 and M523. Each offers a combination of modulation modes and data rates as shown below designed to match the needs of various users without paying for features not needed. In addition a user can upgrade a modem from one version to another at a very nominal cost when requirements change.

  • The M505 is designed as a direct replacement for the PSM-4900 modems. It's data rate and modulation modes are almost the same, plus it has a built-in IBS Multiplexer and Reed-Solomon capability. If the requirement is to add to existing systems using QPSK modulation and either Viterbi, Reed-Solomon or TPC then this is the right modem.
  • The M511 fits the requirements of users who need higher data rates up to 10 Mbps, and/or 8PSK with Trellis Code modulation. The built in Reed-Solomon allows it to operate in the normal 8PSK, TCM, Reed-Solomon with Viterbi at Rate 2/3 without anything additional needed. This is a good general purpose modem able to meet the needs of Teleports, users whose carriers require 8PSK to minimize bandwidth, and those transmitting video signals.
  • The M523 adds data rates up to 20 Mbps and 16QAM modulation. This modem can provide wideband outbound signals for large Star Networks, or a large channel point to point.

Upgrades from one version to another are accomplished by software/firmware loaded into the modem via a new USB connection on the modem rear panel.

There are currently two hardware options available for the PSM-500 series: TPC FEC cards and Ethernet Interface Cards. The TPC is a plug in card to the main modem board and can be either a 4k block Turbo Product Codes FEC (as in the PSM-4900) or a newer 16k block Turbo Product Codes FEC with higher performance (backward compatible with the PSM- 4900). The Ethernet interface can be either the current "SDMS" type card or a new Satellite Network Interface Processor, or "Snip", which is in development now.

PSM-500 Series IF Interface Versions

PSM-500 Series Feature Matrix

Common Features:

  • Programmable modulation modes.
  • Programmable receive acquisition/tracking range.
  • Typical DSP acquisition time of 315 mseconds at 9.6 kbps QPSK, 71 mseconds at 64 kbps QPSK.
  • Viterbi and Reed-Solomon FEC standard, TPC optional. BER vs. Eb/No performance within 0.3 dB of theoretical. 10-7 BER at 6.0 dB Eb/No (2.8 dB with TPC, 3.5 dB with Reed- Solomon codec).
  • DDS transmit and receive frequency setting in 1 Hz increments.
  • Programmable Interface type.
  • Low power, light weight 1 U case.
  • Built-in IBS Multiplexer with overhead channel, AUPC and Remote Modem Control.
  • Built-in BER Test Set.
  • DDS setting of transmit and receive data rates from 1.2 kbps to 20 Mbps 8 User stored and recallable configurations. Automatic Recovery of stored configurations. in 1 bps increments.
  • Viterbi FEC codec programmable to rate 1/2, 2/3, 3/4, 5/6, 7/8 and disabled.
  • Wide AGC range.
  • Full front panel control with keypad, LCD display and LED status.
  • Fully programmable from either front panel or remote command without jumpers.
  • Built-in 1:1 Redundancy.
  • Designed to use internal or external G.703 and Ethernet interfaces.
  • 8 User stored and recallable configurations. Automatic Recovery of stored configurations.