Rohde & Schwarz R&S UPP, User Manual

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Maintenance and Instrument Interfaces
R&S
®
UPP
880 User Manual 1411.1055.32 ─ 10
Figure 9-1: Pin assignment of IEC/IEEE-bus interface
9.4.1.2 IEC/IEEE-bus lines
●
Data bus with 8 lines DIO 1...DIO 8
Data is transferred parallel by bit and serial by byte in ASCII/ISO code. DIO1 is the
bit with the lowest value and DIO8 the bit with the highest value.
●
Control bus with 5 lines:
– IFC (Interface Clear):
Active LOW resets the interfaces of the connected instruments to their initial
setting.
– ATN (Attention):
Active LOW signals the transmission of interface messages
non-active HIGH indicates the transmission of device messages
– SRQ (Service Request):
Active LOW allows the connected instrument to send a service request to the
controller.
– REN (Remote Enable):
Active LOW allows switchover to remote-control mode.
– EOI (End or Identify):
This has two functions in conjunction with ATN:
ATN = HIGH Active LOW indicates the end of data transfer.
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.
– NRFD (Not Ready For Data):
Instrument Interfaces