GPIB OPERATION | PROGRAMMING EXAMPLES |
488.2This function uses the status registers to synchronize the GPIB commands and
General Send/ | return data if a query command was used. The system waits until the command |
Receive System | string has been completed and then checks to see if any data is on the GPIB out- |
| put buffer. If so, the data is returned in the Result$ argument and any error code |
| generated in receiving the data is returned in the Result_Code% argument. |
| For example: Use 4882SendReceive(0, 13, “O 1”, Result$, Result_Code%) to re- |
| turn a reading from the ML2430A Series. |
| Note that this function is written in “pseudo code” and cannot be executed as is. |
Function 4882SendReceive (Board%, Addr%, cmdstring$, Result$, Re- sult_code%) as integer
‘Set up SRE and ESE values first, then process User ’ commands, then do *OPC
cmd$ = “*ESE 49; *SRE 48; ” + cmdstring$ + “; *OPC”
‘Send the command string
Call DLLsend(Board%, Addr%, cmd$, Len(cmd$), Nlend, ibsta%, iberr%, ibcntl&)
‘Wait for either the MAV_bit (Message Available)
‘or/and the ESB_bit (*OPC)
WaitSRQ(Board, Address, MAV_bit + ESB_bit, stb)
If (stb And MAV_bit) Then
‘Read the data string out from the ML2430A
Result_Code% = ReadML2430A(Board, Address, Result$)
'If we did not have the ESB_bit set, wait for ‘ it again (*OPC will set this)
If (stb And ESB_bit) = 0 Then WaitSRQ(Board, Address, ESB_bit, stb)
End if
‘Check if anything went wrong by asking for the ESB register
Call DLLsend(Board, Address, “*ESR?”, 5, NLend, ibsta%, iberr%, ibcntl&)
‘Wait for it to return the data on the output queue. WaitSRQ(Board, Address, MAV_bit, stb)
ReadML2430A(Board, Address, ESB)
‘Read the ESB value
‘Check the ESB for the OPC bit being set
‘(pending commands complete).
If (Val(ESB) and 1) Then 4882SendReceive = True
'Everything sent
end if
‘Now check if anything has gone wrong. If (Val(ESB) And CMD_ERR_bit) Then
4882SendReceive = Command_Error ElseIf (Val(ESB) And EXEC_ERR_bit) Then
ML2430A OM | |
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