5

Remote Operation

Introduction

Chapter 3 introduced you to the basics of remote operation and provided a few simple examples using a Series 200 computer as the HP-IB controller. This chapter contains all the information required to control your power supply remotely and discusses in greater detail how each of the commands can be implemented. The material covered is intended for any controller capable of using the HP-IB interface functions mentioned in Interface Function, on this page.

Four major sub-sections are discussed. These are:

1.HP-IB Operation

2.Programming Syntax

3.Initial Conditions

4.Power Supply Commands

The HP-IB section briefly describes the HP-IB interface functions to get you acquainted with remote programming using the HP-IB. Under Programming Syntax, the syntax of all commands, the numeric data formats and the programmable ranges for all models are given. Initial Conditions highlights the initial values of all the parameters at power-on. Power Supply Commands will describe all the commands which can be used to program the supply's functions including status reporting, error handling, protection features, and voltage and current programming. The power supply commands are summarized in Appendix C.

The examples are written in a generic form to make adaptation to your controller easy. You should be familiar with the use of your controller and its instruction set and how the power supply commands can be incorporated in your controller commands. If you are not familiar with the operation of the power supply, you are advised to read through Chapters 2 through 4 first.

HP-IB Operation

Interface Function

Remote control is implemented by the HP-IB. It enables instructions to be sent from an external computer equipped with an HP-IB interface. The power supply implements the following IEEE-488 Interface Functions:

SH1- Source Handshake

SR1 - Service Request

AH1 - Acceptor Handshake

RL1 - Remote/Local

T6 - Talker

PP1 - Parallel Poll

L4- Listener

DC1 - Device Clear

The source handshake, acceptor handshake, talker and listener functions are implemented by the interface circuits of the power supply and the controller. The ADDR annunciator indicates when the power supply is addressed to listen or talk. (The talker function includes the Serial Poll, see page 62).

Service Request. This is a message which can be initiated by the power supply to request service from the controller. When the supply is requesting service, it asserts the service request (SRQ) line on the HP-IB to interrupt the controller

Remote Operation 61