Envision Peripherals NV3128 - Manual (Page 22)

NV3128 RS-422A Machine-Control Data Switch 1-12
MULTIDROP COMMAND CHAINS
Gating off the response transmitter in a controlled port is an effective and
transparent technique to resolve bus contention in a multi-drop command
chain. In such a mapping, the controlling device sends commands to multiple
destinations, but only one destination is allowed to respond. All other
controlled-port transmitters are gated off. By design, the NV3128 controller
allocates the response transmission path to the first target connected to the
source, therefore the user designates the responding machine by the ordering
of his take salvo.
1.3 I/O
A passive connector-interface backplane couples the active I/O modules and
their external connections. Active modules can thus be removed without
disturbing external cabling.
Data port connectors are RS-232 9-pin D. Video reference input ports are
BNC. A female, 9-pin D connector recieves the serial router control system
cable, and a 37-pin female D connector implements a parallel router-control
interface (older frames only). Both control interfaces and both reference
inputs provide unbuffered loop-through connectors.
1.4 PHYSICAL
Physically, the NV3128 frame installs in a 19" EIA equipment rack. Its
aluminum frame requires no additional cooling, and will operate in ambient
temperatures in the range from 0-50 degrees celcius. The 8 rack-unit high
frame houses two backplanes, one for inter-module signal traffic, the other
mounting I/O connectors. The active modules are inserted from the front of
the frame. The modules consist of:
·
Crosspoint Assembly (1) EM0041-XX
· I/O Assembly (2 - NV3128, 1 - NV3064-D) EM0040-XX
· Universal Control (1, redundant 2nd optional) EM0134-XX
· Power Supply (1, redundant 2nd optional) PS2001-01