Black Box IC026A-R2, IC026AE-R2 manual Data Lines, Multiline Commands

Page 58

RS-232↔IEEE 488 INTERFACE CONVERTER

		1st Data Byte		2nd Data Byte
	DIO-8
	(composite)
	DAV
	Source		Valid	Not	Valid	Not
			Valid			Valid
	NFRD	All	None	All	None
	NFRD	Ready	Ready	Ready	Ready
	Acceptor	Ready	Ready	Ready	Ready
	Acceptor
	NDAC	None	All	None	All
	NDAC	Accept	Accept	Accept	Accept
	Acceptor	Accept	Accept	Accept	Accept
	Acceptor

Figure 6-2. IEEE Bus Handshaking.

6.6 Data Lines

The GPIB provides eight data lines for a bit-parallel/byte-serial data transfer. These eight data lines use the convention of DIO1 through DIO8 instead of the binary designation of D0 to D7. The data lines are bidirectional and are active low.

6.7 Multiline Commands

Multiline (bus) commands are sent by the Active Controller over the data bus with ATN asserted. These commands include addressing commands for talk, listen, Untalk, and Unlisten.

6.7.1 GO TO LOCAL (GTL)

This command allows the selected devices to be manually controlled. ($01)

6.7.2LISTEN ADDRESS GROUP (LAG)

There are 31 (0 to 30) listen addresses associated with this group. The 3 most significant bits of the data bus are set to 001, while the 5 least significant bits are the address of the device being told to listen.

58

Image 58

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 IEEE-488 Interface SpecificationsSerial 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 Peripheral-Mode Operation Peripheral OperationSerial and Ieee Input Buffers 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 History Ieee 488 PrimerGeneral Structure 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