Note

Addressing the Digitizer over HP-IB

Addressing the Digitizer using an Embedded Controller

For compliance with European EMC standards EN 55011 and EN 50082-1, backplane connector shields are included with each

HP E1429A/B digitizer ordered. The shields need only be installed in the VXI mainframe if it is necessary to comply with these standards.

Devices in the Series C mainframe and in the servant area of the HP E1406 Command Module are located by an HP-IB address. The HP-IB address is a combination of the controller’s interface select code, the Command Module’s primary HP-IB address, and the device’s secondary HP-IB address. An address in this form appears as:

70905

Interface Select Code (7): Determined by the address of the HP-IB interface card in the controller. In most Hewlett-Packard controllers, this card has a factory set address of 7, including the HP 82335 HP-IB Interface Card (this card was used with an HP Vectra AT compatible personal computer to create the C programs on the example programs disk).

Primary HP-IB Address (09): This is the address of the HP-IB port on the Command Module. Valid addresses are 0 to 30. The Command Module has a factory set address of 9.

Secondary HP-IB Address (05): This address is derived from the logical address of the digitizer by dividing the logical address by 8. Thus, for the HP E1429A/B digitizer factory set logical address of 40, the secondary address is 05.

As a message-based device, the HP E1429A/B digitizer can easily be programmed across the VXIbus backplane from a HP E1499A V/382 embedded controller. The select code of the VXI interface board in embedded controllers is typically 16. Since no secondary HP-IB address is required when programming over the backplane, the logical address of the HP E1429A/B digitizer is combined with the VXI interface select code:

1640 (for device logical address 40; range = 01 to 99)

If the digitizer’s logical address is changed to a value greater than 99, the address becomes:

160xxx

Chapter 1

Getting Started 19

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HP E1429A manual Addressing the Digitizer using an Embedded Controller, Addressing the Digitizer over HP-IB