# Exercise: interpreting legacy instrument FSC code, and comparing to an NVI FSC

The 5522A FSC provides a great mechanism for comparing the newer NVI FSCs (5522A) to legacy instrument FSCs (5520/M5520).  By learning more about NVI FSCs, the goal is to help you become more proficient, and efficient, at writing MET/CAL procedures.

Most of us are very familiar with writing one line 5520 FSC statements to source voltage and current, so I'll skip over those and head to a slightly more difficult example.  Can you to decipher the following pair of M5520/5520 FSC lines.  This is an open book "test", so please use the FSC help if needed!

1.001  M5520        10mV
1.002  5520          100mV                                          AX S  2W

• What mode will this place the calibrator in?

• What is the voltage coming out of each active output?

• What is the evaluation quantity?

• How would you achieve this same setup using the 5522A FSC?

After some discussion on this one, including a comparison to the 5522A version of this setup, we'll move on to more complex examples.

Date I've received a few emails on this topic since it was posted originally, so there appears to be some interest in this topic.  Here are the answers:

1. Dual DC Voltage
2. Normal output = 10 mV, Aux Output = 100 mV
3. Evaluation quantity is 100 mV from the Aux Output.
4. The equivalent 5522A statement is below.
` 1.003 5522A Mode = DualDC_Voltage 1.003 5522A +AuxVoltage = 100 mV; NormalVoltage = 10 mV`

Which version is easier to write, and then read and interpret during later procedure maintenance?

` 1.016 M5520 1mV O EL 1.017 5520 1mA S 2W` francois lamarche

I want to measure (and test against limits a resitance using the 5522A NVI FSC

what's the right syntax?

in other words, how to you translate...

1.036  5500         50.00Z         2.00%                           ZM    2W

to 5522A? Dale Chaudiere

5500 FSC MOD3 = "ZM" is Scope Input Impedance Measurement.  The 5522A FSC does not support the Scope Calibration options.  The 5080A and 55xxA Oscilloscope Calibration options installed in the 5080A, 5500A, 5502A, 5520A, and 5522A, and the 5800A and 5820A Oscillocope Calibrators are now supported by the O_CAL NVI (Name = Value, Instrument) FSC.

The correct translation is:

1.036 O_CAL Mode = ImpedanceMeasurement

1.036 O_CAL +Resistance = 50.00 Ohms; Setup

1.037 TARGET -m

1.038 O_CAL Mode = ImpedanceMeasurement

1.038 O_CAL +Resistance = 50.00 Ohms; Read

1.039 MEMC 50.00 2.00% francois lamarche

Dan, nice command, but will it automatically carry over the uncertainty associated with the 5522a?

if not, how would I calculate it? Dale Chaudiere

The O_CAL FSC always uses the correct accuracy file for the instrument used at run time.   For example, if O_CAL is "Device Mapped" to "Fluke 5522A" asset "XYZ" and "XYZ" is on a 1 year recall interval, the 5522A 1 year accuracy file will be used.  You can verify this by select DEBUG=>Trace=>Accuracy in the Editor, and observing the stream in the Output Window. francois lamarche

THis is very nice - thanks for the explanation

A question though, if we need to add an accuracy in quadrature for the connection fixture between

the O_CAL and the UUT, is there a way to retrieve the O_CAL's accuracy as a term in the MATH calculation of an accuracy? Dale Chaudiere

The MATH FSC REFACC() function always returns the reference accuracy established by the executed instrument FSC.  REFACC() returns in units specified in the instrument FSCs.

Example:

1.036 O_CAL Mode = ImpedanceMeasurement

1.036 O_CAL +Resistance = 1.00 MOms; Setup

1.037 TARGET -m

1.038 O_CAL Mode = ImpedanceMeasurement

1.038 O_CAL +Resistance = 50.00 Ohms; Read

1.039 MATH   L = REFACC()

At this point, if the 5522A is used, L will contain the 5522A Impedance Measurement accuracy of the 5522A reading in MEM.  Both L and MEM will be units of megohms.

You can then combine the accuracy with other uncertainty components after normalization.

MATH L = L / CONF("Fluke 5522A") Dale Chaudiere

You should probably convert to proportional parts before combining with other uncertainties.

Example (%):

MATH L = L / MEM * 100