Product Description

The Matrix Scanner type MSS 1601 is a triple–width CAMAC module designed to scan 256 or 320 isolated
1KV contacts arranged as 16 x 16 or 20 x 16 matrix. Thus the unit drives an optically isolated ’Column’ output line (one of 16) and scans the 16 (or 20) optically isolted ’Row’ input lines connected to that column via plant contacts. The state of each contact (open, or closed, or changed) chosen to raise an alarm is set by program.

The state of a memory determines the type of condition which causes an alarm code to be produced, i.e. whether contact ’open’; contact ’closed’; or contact ’changed’ state. The same contact mode memory may also be programmed to disable any alarm condition on particular points.

Any alarm status words produced by the selected condition are stored in a 64–word FIFO register and may be read by the System Controller and include the contact point number (in the range 0–255 or 0–319), the contact state (open or closed), a scan number code, and a module code all combined into a 24–bit word. Then the next ’Column’ line is driven and so on.

Provision exists for reading the initial state of the whole matrix as well as other internal memories, and an isolated contact closure is made available at the output connector which changes state every 4th or 256th scan thus allowing a known status change to occur for checking system integrity. This is called the watchdog contact.

A 17th or 21st input from the matrix can be used for checking the integrity of the matrix itself. For the scanner’s command table please see overleaf.