Black Box IC026A-R2, IC026AE-R2 Use of Serial and Bus Terminators, Ieee 488 Bus Implementation

Page 50

RS-232↔IEEE 488 INTERFACE CONVERTER

5.5 Use of Serial and Bus Terminators

The interface converter can be configured to provide RS-232-to-IEEE-488 and IEEE-488-to-RS-232 terminator substitution. This is useful when interfacing a serial device that only issues carriage return [CR] as an output terminator to an IEEE controller that expects a carriage return followed by a line feed [CR-LF].

In this previous example, the serial terminator should be selected for CR Only while the IEEE terminator is set to CR-LF. When a serial CR character is received it is discarded and substituted with an IEEE CR followed by an IEEE LF. In the IEEE to serial direction, the IEEE CR is unconditionally discarded. Upon receipt of the IEEE LF a serial CR is substituted.

The interface converter can be made totally data-transparent by setting both the serial and IEEE terminators to be CR Only or LF Only. The choice of appropriate terminators may be determined by inspection of the serial device and IEEE controller’s instruction manuals. See Chapter 3 of this manual for instructions on selecting the interface converter’s serial and bus terminals.

5.6 IEEE 488 Bus Implementation

The interface converter implements many of the capabilities defined by the IEEE 488 1978 specification. These are discussed in the following sections. The interface converter does not support or respond to these bus uniline and multiline commands:

Remote Enable (REN)

Go to Local (GTL)

Group Execute Trigger (GET)

Local Lockout (LLO)

Take Control (TCT)

Parallel Poll (PP)

Parallel Poll Configure (PPC)

Parallel Poll Unconfigure (PPU)

Parallel Poll Disable (PPD)

50

Image 50

Contents RS-232↔IEEE Interface Converter RS-232↔IEEE 488 Interface Converter Trademarks Used in this Manual RS-232↔IEEE 488 Interface Converter NOM Statement RS-232↔IEEE 488 Interface Converter Contents RS-232↔IEEE 488 Interface Converter Contents Serial Interface SpecificationsIEEE-488 Interface Specifications GeneralIntroduction DescriptionAbbreviations Inspection ConfigurationGetting Started Serial PortSW3 Serial Port Settings Switch SW1 Selecting the Serial Baud Rate Switch SW1 Selecting the Serial Word Length Data Bits Switch SW2 Selecting the Serial Parity Switch SW1 Selecting the Serial Handshake Switch SW2 Selecting the Serial Terminator Selecting Terminator SubstitutionSelecting the Mode Switch SW3 Selecting the Ieee Bus Terminator10. Switch SW2 Selecting the Mode Selecting the Ieee AddressFeature Selections Serial Interface 15. Selecting RS-232 or RS-422 Signal Levels Clear To Send-Input-Pin RxD Receive Data-Input-PinTxD Transmit Data-Output-Pin Request To Send-Output-Pin+RxD Receive Data Plus-Input-Pin Vtest Test Voltage-Output-PinGnd Ground-Pin +TxD Transmit Data Plus-Output-PinRTS CTS General DSR RTS CTSGetting Started Controller Operation Controller-Mode Serial to Ieee OperationSerial and Ieee Terminator Substitution Talk-Back Features Ieee Address SelectionSwitch SW1 Enabling or Disabling Talk-Back on Terminator Switch SW2 Enabling or Disabling Talk-Back on Timeout 7470A SP1PA1000,1000PDPA1000,6000PUSP0Plotter Applications A PC-Based Graphics System SW3 MacPlot Configuration Screen Setting the Internal DIP Shorting Jumper for RS-422 SW3 Printer Applications Serial and Ieee Input Buffers Peripheral OperationPeripheral-Mode Operation Ieee Data Transfers Controlled BUS Data Transfers Serial-Poll Status-Byte Register DIO8 Ieee Input Buffer not EmptySerial Input Buffer not Empty RsvNot Defined-Always Ieee Input Buffer FullUse of Serial and Bus Terminators Ieee 488 Bus ImplementationUntalk UNT SW3 View for Ieee Address Selection General Structure Ieee 488 PrimerHistory RS-232↔IEEE 488 Interface Converter Send It to My Address DMMBus Management Lines Handshake Lines Data Valid DAVMultiline Commands Data LinesTalk Address Group TAG More on Service Requests Serial Poll Theory of Operation Address Device Part Number FunctionBoard Layout Component Layout of the Interface Converter’s MotherboardRED BLK Appendix A. Sample Dumb-Terminal Program CLSMultiline Messages SOHHow To Read the Chart Ascii CharacterIndex DIO1 DIO2 DIO3Index SW1 Copyright 1998. Black Box Corporation. All rights reserved