53A-253B – Gaussian Noise Generator Card
OPT 1V – add VXIbus Compatibility
53A-780 – Hooded Connector

• Dual channel
• Designed to be used with the 53A-453 to automatically perform the noise test required by MIL-STD-1553
• Reports results after test completion
• Can be used in other applications requiring a Gaussian noise source

The 53A-253B Gaussian Noise Generator Card is designed to operate with the 53A-453 MIL-STD-1553A/B Bus Simulator Card in order to automatically perform the noise-rejection tests specified by MIL-STD-1553B. The Card may be configured with either one or two channels, allowing two separate 1553 terminal units to be tested simultaneously, if desired.

The 53A-253B Card uses on-card hardware to implement the accept/reject test criteria specified by MIL-STD-1553B, significantly reducing test time, system controller overhead, and user software development. The Card automatically checks remote terminal response data for missing responses. late responses, multiple responses, or responses with the message error bit set. During a noise-rejection test, the system controller can interrogate the Card for the current status of the test, or the Card can be programmed to generate an interrupt to the system controller when the test is completed.

A typical noise-rejection test will take approximately 15 minutes. However, a complete test may run up to two hours depending upon either or both of the following: the actual message rate, and how quickly the unit under test exceeds the MIL-STD-15538 accept/reject test criteria. Since all the accept/reject test criteria are automatically checked by the 53A-253B Card, the system controller is free to perform other tasks during the noise-rejection test.

Built-In-Test Equipment (“BITE”) is provided by LEDs to the Card’s front edge that provide status information concerning the noise-rejection test in progress.

Number of Channels:
One or two.

Error Count:
0 to 41.

Word Count:
0 to 33 x 10^7

Gaussian Noise Output Amplitude:
140 mV RMS into a 70 Ohm load.

Gaussian Noise Bandwidth (3 dB):
1 KHz to 4 MHz.

Data Returned As:
Integer ASCII Characters.

Parameters Returned:
Test-in-Progress status, Pass/Fail status, Error count Word count as a multiple of 10^7 words.

Interrupt Capability:
CDSbus System interrupt on Channel A or B test completion.

Inputs Required (normally supplied by 53A-453):
Bus Controller Word Transmission:
Active low TTL pulse for each bus controller command or data word.
Minimum Pulse Width, 50 nsec.

Unit Under Test Response Transmission:
TTL Level, active for the duration of the status word and data word response.
Message Error Bit:
Active low TTL pulse. Minimum Pulse Width, 50 ns.

Input Loading:
One LSTTL Schmitt-Trigger load.

Programmed By:
ASCII Characters.

Recommended Cable:

Available Option:
OPT 1V. add VXIbus compatibility.