CAMAC C201 Abort Link Generator

R.J. Ducar

Table of Contents

^General Description

This single-width module is the source of the 5MHz permit signal that is integral to the operation of the abort loop.

Normal operation of the module is as follows:

  1. Given the initial condition that the abort loop has been tripped, a reset abort loop command is generated manually from page T67. This is event $48 for the Tevatron.
  2. Event $48 is detected by an on-board TCLK decoder and gates an on-board 5MHz oscillator signal to the abort link for 100uS.
  3. If all of the CAMAC 200 Abort Concentrator modules in the system are generating permit condition, the 5MHz signal will transmit all the way around the loop and return to the module after approximately 34uS. Detection of the return signal will enable the continuing gate of the 5MHz signal to the link.
  4. If any CAMAC 200 fails to generate a permit condition during reset, the 5MHz signal will be latched off after 100uS. If any CAMAC 200 fails to generate a permit condition once the loop is made up, the 5MHz signal will be latched off 1/2uS after cessation of the return signal is detected. Ring=wide removal of the 5MHz signal is thus effected.

As a diagnostic feature, the 5MHz permit signal may be continuously gated from the 201 module. Under such a condition, LAM will be generated and errors may be reported from page T67.

^CAMAC Commands

CAMAC Commands
F(6)A(0)Reads module number
F(9)A(0)Reset Module
Logical OR with Z*S2 and power up clear.
Sets normal conditions for 5MHz output and turns LAM off.
F(28)A(0)Continuous mode OFF
For 5MHz output signal normal condition.
LAM is off.
F(30)A(0)Continuous mode ON
For 5MHz output signal diagnostic condition.
LAM is asserted.

^Front Panel

The 201 module front panel supports the following:
Front Panel
N LED(Stretched)
LAM LEDAsserted when 5MHz output signal is continuously gated on.
Link Reset LED(Stretched)
Flashes upon receipt of event $48 or external link reset input.
Link Reset view LEMOView of 100uS gate.
74128 driver, 50 Ohm compatible.
External Link Reset In LEMOPositive edge trigger of 100uS gate.
Input is terminated in 100 Ohms.
Abort Link View LEMOView of abort link signal after transmission around the loop. This is a 5MHz square wave when the loop is made up.
74128 Driver, 50 Ohm compatible.

^I/O Connector

C201 I/O Signals
5LAbort Link Return Input5RGND
7LAbort Link 5Mhz Signal Output7RGND
10L 10RGND
11L 11RGND
12L 12RGND
13L 13RGND
14L 14RGND
16L 16RGND
17L 17RGND
18L 18RGND

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