User manual

Part 1: Making the Remote Connection
VICP Headers
The format of the header sent before each data block of a VICP transmission, both to and from the
instrument, is set out in the following table:
Byte Number Purpose
0 Operation
1 Header Version
2 Sequence Number*
3 Spare (reserved for future expansion)
4 Block Length, (bytes of data), MSB
5 Block Length (bytes of data)
6 Block Length (bytes of data)
7 Block Length, (bytes of data), LSB
* The sequence number is used to synchronize write/read operations to simulate 488.2 “discard unread response”
behavior. Valid range is 1 to 255 (zero is omitted intentionally).
VICP Operation Bits
Operation bits are as follows:
Data Bit Mnemonic Purpose
D7 DATA Data block (D0 indicates termination with/without EOI)
D6 REMOTE Remote Mode
D5 LOCKOUT Local Lockout (Lock out front panel)
D4
CLEAR Device Clear (if sent with data, clear occurs before data block is passed to parser)
D3 SRQ SRQ (Device to PC only)
D2 SERIAL POLL Request a serial poll
D1 Reserved Reserved for future expansion
D0 EOI Block terminated in EOI
Logic 1 = use EOI terminator
Logic 0 = no EOI terminator
VISA Addressing
Code strings such as "TCPIP::<IP address>::1861::SOCKET" may or may not work when using VICP
depending on how the application handles instrument responses. The data returned will include header
information that needs to be parsed, and allowances must be made to trap situations where a transfer is
not complete, or where there is an unread response from the instrument. SOCKET connections should
work properly if you are using the VICP Client Library.
Teledyne LeCroy developed the VICP Passport to handle socket connections more reliably when using NI-
VISA. Instead of "TCPIP::<IP address> . . .", use "VICP::<IP address>" to make the connection.
1-7