User manual
64
© 2008, Elektro-Automatik GmbH & Co. KG
EN
About the interface cards
Averaging
(Specification according to „1999 SCPI Command reference“:4 Calculate Subsystem)
CALCulate
:AVERage:COUNt? -><1..100> Queries the number of measurements used for averaging
:AVERage:COUNt <1..100> Set the number of measurements for an averaged actual value
(Default is 100,
*RST has no effect)
:AVERage:AUTO B2 Using „ONCE“, only one measurement will be performed
Using „ON“ repeats the measurement automatically
The measurements always are for U
act
, I
act
, P
act
*RST cancels the averaging
:AVERage:STATe B0 „ON“ starts, „OFF“ stops averaging
Examples:
CALC:AVER:COUN8 If actual values are queried with MEAS:, the average value of the last 8 measurements is returned
CALC:AVER:STATOFF Stops averaging, only the last measured values is delivered.
Attention! This setting is not saved. It is reset to its default value 100 after a restart of the device.
The averaging performs x measurements of all actual values within a certain interval and these measurements are used to
form the average value. It can be queried with the MEAS: command, after the measuring cycle is finished.
If averaging has been turned on by CALC:AVER:STAT ON, a measurement cycle is started by *TRG (at setting CALC:
AVER:AUTO ONCE), which measures depending on CALC:AVER:COUNT x times before the OPC bit in the status Event
Status Register ESR is set. This is signalising, if enabled, the state via the esr bit in the status register STB. The status
register STB automatically generates a service request call.
Only after this, the measured values are allowed to be read. In case they‘re read too early, the interface will return ERR
-200, Execution error.
If averaging has been turned on with CALC:AVER:STAT ON and CALC:AVER:AUTO ON was set, the measurement cycle
does auto-repeat. The measured values and the device status are recorded every 20ms, so that at the default setting of 10
measurements the OPC is set every 2000ms. The measured values can be read out, after bit OPC has been queried.
Attention! When using averaging, it is required to query the bit OPC before the measured values are read out with
MEAS. Else an error is returned.
4.5.9 Errors
Errors are collected in an error queue. The err bit indicates, if a new error has occured. It can be queried with a service
request call. The error queue is queried seperately and is automatically cleared when read.
<ERR> Message Description
0 “No error“ Error queue empty, no error present
-100 “Command error“ Invalid command used
-101 “Invalid character” ...in the command string
-102
“Syntax error“
-103 “Invalid separator“
-108 “Parameter not allowed”
-109 “Missing parameter“
-113 “Undefined header“ Command unknown
-120
“Numeric data error”
-131 “Invalid suffix” or unit
-141 “Invalid character data“
-151 “Invalid string data“
-200
“Execution error“ General error, used for various situations
-201-
“Invalid while in local” Device is local, so remote mode is blocked