Link and Mission Simulation & Validation

Model 236 PCM / PAM Simulator
Model 236

The GDP Space Systems Model 236 PCM/PAM Simulator addresses the need to perform cost effective PCM or PAM clock and data simulations. The unit facilitates widespread use of PCM by combining the most desired application features users into one unit. The Model 236 is ideal for PCM users who do not have the time or the inclination to become simulator programmers. The Model 236 allows users to directly describe a telemetry format in response to plain language prompts using the front panel keyboard and high-contrast vacuum fluorescent display. The format consists of a frame filled with a background pattern over which unique data words may be superimposed. A subframe may also be added to the format and unique words placed anywhere within the frame/subframe matrix. The unique words may also be distributed throughout the frame and/or subframes in a super commutated manner. The Model 236 generates PCM data at rates up to 40 Mbps. Output data rate is determined by an external clock source, or by an internal frequency synthesizer. The internal synthesizer may be programmed for the desired data rate by direct entry from the front panel or via the Remote Control interface. The Remote Control interface can be used for all format, data rate and code selections.

 

  1. 1 Bps to 40 Mbps operation with 1 Hz resolution
  2. Internal Frequency Synthesizer
  3. Frame and Subframe capacity
  4. Bipolar output option
  5. Virtual Instrument Software for remote control
  6. All IRIG PCM Codes and RNRZ-L
  7. Selectable RNRZ-L patterns, forward and reverse (2N-1; N=7, 9, 11, 15,17, 20, 23)
  8. Convolutional Encoder (R=1/2, K=7)
  9. Local and Remote Control
  10. Non-Volatile Format Storage
  11. 8192 unique frame data words
  12. 8192 unique subframe datawords
  13. Dynamic data changes during simulation
  14. TTL, RS-422 and RS-232 outputs

Data Format
4-16 Bits/word
1-8192 frames/subframe
1-8192 words/frame

Data Sources
ID counter, 12 bits
General Data Word
Frame:
16 Bits x 8192 Unique Words
Subframe:
16 Bits x 8192 Unique Words

Synchronization Types

FRAME:
Normal
Alternating FS
1-64 bit sync pattern

SUBFRAME:
SF Sync Complement
Recycle Pattern
ID counter up/down

Bit Rate
1 bps through 40 Mbps NRZ-L

Outputs
TTL:
50 Ohm
BNC Connectors
NRZ-L, TTL Data CODE,
TTL Coded Data
NRZ-L,M,S
RNRZ (2N-1; N=7, 9, 11, 15,17, 20, 23)
BIO-L,M,S
DM-M/S
Convolution Encoder:
R=1/2, K=7 0° & 180° degree clock
PAM:
Pulse Amplitude Modulation (Optional). BNC
BIP:
Bipolar Data Output (Optional). BNC
RS232:
DB25S connector
Coded data
NRZ-L data
0 & 180 degree clock
RS422:
DC37S connector
Coded data
NRZ-L data
0 & 180 degree clock

Remote Control
RS232 Serial Interface:
DE9S connector Asynchronous start-stop serial data link Baud rate (300-9600), parity, and stop bits.
IEEE-488 Interface (Option):
Standard IEEE connector

Local Front Panel Control

VF Display and Keypad
Bright, high contrast Vacuum Fluorescent (VF) 2-line by 40-character display format Twenty (20) position keypad

LED Indicators
RUN (Green)
HALT (Red)

Test Point Outputs:
BNC Connectors:
NRZ-L data
CLK, 0 degree clock
CODE, Coded data
FRM, Frame Pulse
PAM, Pulse Amplitude Modulated (Optional)

Miscellaneous
Power:
108/240VAC, ±10% 47-63 Hz
Temperature:
10° to 50° C operating
Humidity:
15 to 95%
Size:
19"W x 3 ½"H x 20"D
Weight:
20 lbs.

PAM Output Option
Channel rate:
up to 320 K Samples/sec
Resolution:
1 part in 256 (8 bits)
Output Range:
0 to +5 volts into 75 ohm load
Linearity:
±½ LSB
Accuracy:
±½ LSB
Stability:
±20 ppm/degree C over 10 to 50 C

Bipolar Output Option
Amplitude:
50mV to 10Vp-p (open circuit)
Offset:
0 to ±5 Volts (open circuit)
Offset plus peak signal is limited to ±10V