User manual

Chapter 4 AMCI Module Addressing

ADVANCED MICRO CONTROLS INC.

This chapter explains how to address a 2762-17 in a programmable controller system.

Remember that a 2762-17 performs concurrent block and single transfers.

When you configure your programmable controller system, you specify a unique address for each slot

of each chassis in the system. An I/O Rack number and an I/O Group Number make up each address. A

Module Slot number further specifies a block transfer address.

Note that an I/O Chassis is not the same as an I/O Rack. An I/O Chassis is the physical

enclosure that the processor and I/O modules plug into. An I/O Rack Number is part of a

modules' address in the system. Each I/O Chassis can have ¼ to 4 I/O Racks associated with it.

Definition of Terms

Block Transfer

The transfer of a block of data over the backplane in one scan. A Block Transfer Read

transmits data from an I/O module to the processor. A Block Transfer Write transmits data

from the processor to an I/O module. Up to sixty-four words can be transmitted per block

transfer. The 2762-17 requires block transfers of twelve words.

Single Transfer

The transfer of a single unit (8, 16, or 32 bits) of data over the backplane. The transfer

occurs between I/O Modules and the processors' Input or Output Image Tables. Single

transfers occur automatically every I/O scan and can occur during a program scan with the use

of Immediate Input and Immediate Output Instructions. In addition to using block transfers, the

2762-17 accepts and transmits single transfer data 16 bits at a time.

I/O Rack

The number of I/O Racks in the system, not the number of chassis, define the programm-

able controller system. In PLC-5 systems the first I/O Rack is assigned the number 0. Each

I/O Rack is further divided into 8 I/O Groups.

When specifying a block transfer or single transfer address all I/O Rack and

Group numbers are expressed in octal. (i.e. 00, 01, 02, ... 06, 07, 10, 11, ......)

I/O Group

An I/O Group consists of 16 input and 16 output bits. Eight I/O Groups, numbered 0

through 7, make up a single I/O Rack.

Slot Pair

Backplane slots of an I/O Chassis are numbered consecutively from zero starting at the

leftmost I/O slot. A slot pair is two adjacent backplane slots, the left of which is even

numbered. Most A-B chassis have the slots numbered on the backplane silk screen.

A 2762-17 module must be installed in a single slot pair to operate properly. See

Installing the Module

, Pg. 37. The figures in this chapter show the module in a Slot Pair.