INTRODUCTION
The M-SAT is a newer, later version of the industry standard SAT-19. It provides lower cost, higher speed, more up to date components, more error checking and recovery, as well as a few new features.

It is an intelligent buffered communication interface that allows Unisys/Burroughs TDI (Two-Wire Direct Interface) or Asynchronous three-wire RS-232 terminal networks to be installed on SYNCHRONOUS or ASYNCHRONOUS Multi-Point modem networks. It is not necessary to convert the entire network. Only one M-SAT is required at the location where the conversion is required.

Operating two-wire TDI, or asynchronous RS-232 three-wire terminal networks provides more reliable terminal networks and easier cabling methods. It also allows PCs operating with Poll/Select software packages to be connected to a synchronous network without requiring expensive synchronous interface boards for each PC. The TDI and async RS-232 terminal networks can operate concurrently from the M-SAT. CPS also offers a variety of complementary modem splitters, TDI converters, and twisted pair Hubs to address most any terminal network cabling requirement.

OPERATION
In addition to addressing the Sync/Async protocol conversions, the M-SAT provides the RTS/CTS modem control signal recognition and an elastic buffer that is required for operation on Multi-Point modem networks.

The M-SAT has outstanding protocol error detection and error recovery capability. It prevents streaming terminals from taking down the entire multi-point network.

DIAGNOSTICS
When errors are detected, the M-SAT will flash an error LED to alert the operator as to the occurrence of potential problems from the network, terminals, or environment. For further diagnostics, a serial printer may also be connected to the M-SAT to provide a hard copy audit trail of the error conditions. This may have a number of uses from identifying a specific problematic terminal to providing direction to subsequent troubleshooting efforts.

MODELS
The M-SAT is provided in two different form factors.

1. M-SAT (Figure #1) is housed in a stand alone plastic enclosure. It is connected to the modem and the terminals via the appropriate cables. This version may also be used at the host site as well as to connect a synchronous network to an asynchronous RS-232 or TDI host port. (Figure #2.)
   
2. STAC-M (Figure #3) is a PC board version that is supplied with the appropriate mating connectors and hardware to allow it to be connected to any of CPS's P-CON 48 (Patch Panel Converter) modules. It simply "Stacks" on them. The P-CON is a popular twisted pair Hub that is used for structured wiring installations. It allows TDI or RS-232 terminals to share a twisted pair LAN style cabling topology.