Rohde & Schwarz R&S ZVA 8 - Page 781

R&S
®
ZVA/ZVB/ZVT Rear Panel Connectors
1145.1084.12 8.9 E-3
Always use a shielded cable to connect the GPIB bus interfaces.
Characteristics of the interface
• 8-it parallel data transfer
• Bidirectional data transfer
• Three-line handshake
• High data transfer rate of max. 1 MByte/s
• Up to 15 devices can be connected
• Maximum length of the connecting cables 15 m. The length of a single connecting
cable should not exceed 2 m, if many devices are used, it should not exceed 1 m.
• Wired OR if several instruments are connected in parallel
Pin assignment
Bus lines
1. Data bus with 8 lines D0 to D7 The transmission is bit-parallel and byte-serial in
the ASCII/ISO code. D0 is the least significant bit, D7 the most significant bit.
2. Control bus with five lines
IFC (Interface Clear):active LOW resets the interfaces of the instruments 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 the connected device to send a service
request to the controller.
REN (Remote Enable):active LOW permits switchover to remote control.
EOI (End or Identify):has two functions in connection with ATN:
ATN=HIGH active LOW marks the end of data transmission.
ATN=LOW active LOW triggers a parallel poll.
3.Handshake bus with three lines
DAV (Data Valid):active LOW signals a valid data byte on the data bus.