External Interfaces | LTPH-UM-1088-02, Issue 2 |
| |
RS-232 CRAFT INTERFACECommunication with the ThinMux STS-1 and ThinMux DS3 central processors occur through a standard grounded DB-9 connector (RS-232 Data Communication Equipment interface).
Signals are routed to both multiplexers, and the transmitter of the inactive multiplexer remains in a tristate mode. Pin 5 is the digital ground of all digital components (both multiplexers). See Table 3 on page 17 for interface pinout description.
10/100BASE-T ETHERNET INTERFACECommunication with the multiplexer (STS-1 or DS3) central processors occurs through the standard grounded RJ-45 10/100BASE-T interface for metallic chassis. Similar to the RS-232 interface, signals are routed to both multiplexers; the transmitter of the inactive multiplexer remains in a tristate mode. See Table 4 on page 17 for interface pinout description.
DISCRETE ALARMSIn addition to the various interfaces supplied by the ThinMux chassis, the common access panel (see Figure 4 on page 8) provides access for discrete alarm wiring.
The discrete alarms connection is provided by 0.045-inch wire-wrap pins located on the rear of the chassis (see Figure 1 on page 2). The signals are routed to the multiplexers, where the logic functions are performed. Critical VIS and AUD alarms comprise dry contacts for telemetry applications. The alarms have an independent common connection (serial COM port) to relays; normally open (NO) is provided. Current is limited to 0.5A when a maximum temperature rise of 20°C on traces is desired (as per MIL-STD-275C).
When using a legacy HXU-358 multiplexer, the CRIT VIS, CRIT AUD, and Alarm pins must be left unconnected. For all other multiplexers, these pins may be used as needed.
Other alarms (FE, MIN, MAJ, and CRIT) share the same COM, and only normally open contact is provided as shown in Figure 4 on page 8. Contact closure is made using a solid-state relay photo Metal-Oxide Semiconductor
4 | January 3, 2002 | ThinMux Chassis |