Product Description

The module accepts and priority–sorts up to 23 service–demand signals from modules in the crate plus three external demands and a manually set interrupt. It then feeds the demands to the crate controller in the correct sequence.

The LAM Grader Type LG2401 is a single–width CAMAC module (compatible with CERN Type 064) designed for use with an ESONE Type A or A1 crate controller. It also has facilities for accepting three external demands via Lemo sockets on the front panel and a fourth demand can be set manually by operating a front–panel pushbutton. These are labelled FD1, 2, 3 and 4 respectively. The output from the module is a 24–bit graded–L (GL) pattern which is fed to the crate controller via a rear–panel connector. Priority sorting is achieved by hardware (patchboard) or software (masking).

The patchboard is used to provide an easy method of priority control. It has 26 input pins, 48 output pins and is plugged into the main pcb. The pins can be wired to suit current requirements. Thus, it is possible to change the priority arrangement without altering the main circuit of the module. It may be convenient in some instances to keep 2 or 3 ready wired–up patchboards so that priorities can easily be changed with minimum delay. The 24 bit Demand Mask Register masks the GL lines individually. A logical 1 (low–level) on a W line enables the corresponding GL line (eg W1 enables GL1). It can be preset to “no masking” by a pushbutton on the front panel.

The front panel carries two LEDs. The SEL indicator shows that either the LAM Grader (lit) or crate controller (unlit) is addressed. The GL indicator is lit when at least one GL line is set.

Specification/Command Structure:

Addressed commands – see table 1.
Non–address commands – initialise (Z) enables Demand Master Register and clears FD1–4LAM.

Facilities:

Inputs: (a) 23 L–lines fed in via the rear–panel connector. (b) 3 FD inputs (FD1, 2, 3) fed in via Lemo sockets on the front panel. (c) Manual interrupt (FD4) from a pushbutton on the front panel.

Outputs: (a) 24 GL–lines fed out via the rear–panel connector. (b) 3FD outputs (FD1, 2, 3) taken from Lemo sockets on the front panel. The outputs correspond to inputs (b) and are available until the appropriate demand is executed.