IVI Driver Channel Naming

The IVI driver does not treat a switch card as a set of switch objects, it treats the switching circuitry like a 'black box' and applies channel labels to each terminal. The channel labels applied are chosen by the driver and are created to represent the functionality of the terminal.

A tool to explore the channel names of Pickering switch cards is available from our download site: ivi_data_inspector.exe

The normal channel labels applied for common switch types are shown in the following diagrams.

Simple Switch

Matrix

Multiplex

Changeover Switch

Simple switch

The channel names applied to a simple switch are 'com' and 'ch'; where there are a bank of such switches, these are followed by numerals to indicate the position of the switch in the bank.

So, a bank of 4 simple switches will be given the channel names:

com1,ch1
com2,ch2
com3,ch3
com4,ch4

So, to operate such a switch in the IVI driver, commands are formatted thus:

pi40iv_Connect(vi, "com1", "ch1");
pi40iv_Disconnect(vi, "com1", "ch1");

If a card contains multiple banks of simple switches, an addtional suffix indicating the bank is added:

comA1, chA1 etc for the first bank
comB1, chB1 etc for the second bank
etc

Matrix

The channel names applied to a matrix are 'x' and 'y';these are followed by numerals to indicate the row and column number.

So, a 4x4 matrix will be given the channel names:

x1,x2,x3,x4,y1,y1,y3,y4

So, to operate a matrix in the IVI driver, commands are formatted thus:

pi40iv_Connect(vi, "x1", "y1");
pi40iv_Disconnect(vi, "x1", "y1");

If a card contains multiple matrices an addtional suffix is added to indicate the matrix, eg:

xA1, yA1 etc
xB1, yB1 etc
etc