R&S 1129.7246.03, Operating Manual

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Operating Manual 1302.6163.12 - 03 8.3
R&S ESU Maintenance and Instrument Interfaces
Instrument Interfaces
8.3.1.1 Interface Characteristics
• 8-bit parallel data transfer
• bi-directional data transfer
• three-line handshake
• high data transfer rate
• up to 15 instruments can be connected
• maximal length of the interconnecting cables 15 m (single connection, 2m)
• wired-OR connection if several instruments are connected in parallel.
Fig. 8.49 Pin assignment of GPIB interface
8.3.1.2 Bus Lines
Data bus with 8 lines DIO 1 to DIO 8.
The transmission is bit-parallel and byte-serial in the ASCII/ISO code. DIO1 is the
least significant, DIO8 the most significant bit.
Control bus with 5 lines.
IFC (Interface Clear),
active low resets the interfaces of the devices connected to the default setting.
ATN (Attention),
active low signals the transmission of interface messages
inactive high signals the transmission of device messages.
SRQ (Service Request),
active low enables a device connected to send a service request to the controller.
REN (Remote Enable),
active low permits the switch over to remote control.
EOI (End or Identify),
has two functions in connection with ATN:
active low marks the end of data transmission when ATN=high
active low triggers a parallel poll when ATN=low.
12
1
13 24
SHIELD SRQ NDAC DAV DIO4 DIO2
LOGIC GND GND(10) GND(8) GND(6) DIO8 DIO6
GND(11) GND(9) GND(7) REN DIO7 DIO5
ATN IFC NRFD EOI DIO3 DIO1