Status and Error Messages

The EIS software techniques provide both status and error messages as they run. These messages are displayed in the lower left-hand corner of the runner window.

Errors in how the measurement of the last point was terminated

In all cases, an impedance data point was measured.

Measurement OK The FRA has been able to make a measurement within the precision limit set in the script. The data point is most likely of high quality.
Timeout The FRA could not make a known good measurement within a set time-period. Readings were obtained but they did not stabilize within the precision limit in the script.

The impedance data point may or may not be a good estimate of the test cell’s impedance.
Cycle Limit The FRA could not make a known good measurement within a set number of AC cycles. Readings were obtained but they did not stabilize within the precision limit in the script.

The impedance data point may or may not be a good estimate of the test cell’s impedance

Errors when the FRA failed to take an impedance data point

You are asked if you wish to retry the measurement, go to the next frequency, or terminate the entire experiment.

Unable to Control Signal Often the FRA must generate an AC signal larger than that requested in Setup, in order to obtain a potential signal that is close to the requested value. This happens most often at higher frequencies, when the working electrode impedance is smaller than the cell’s solution resistance.

When you see this error message, the FRA cannot generate a large enough signal. It is at its output amplitude limit and the measured potential signal is still too small.

You may be able to fix this problem by

a) increasing the conductivity in the cell’s electrolyte

b) lowering the requested AC-signal magnitude

c) avoiding higher frequencies.
Stuck in Reading Loop The script made too many attempts to measure the impedance at this frequency. The automatic setting of the FRA and potentiostat parameters has been unable to find a set of parameters that give meaningful readings.

If this occurs on the first frequency in the spectrum, make sure the initial guess is close to the cell impedance. If this occurs at high frequencies, try a lower frequency.
Unable to set current range The script calculated that it needs to be in an invalid current range to make the measurement. For example, the script calculates that the current will be 1000 mA and it knows that the potentiostat used is a Reference 600 with a 600 mA current limit.
User Interrupt You clicked Skip-F2 during a measurement.
Invalid Measurement The FRA is unable to make any meaningful measurement on either the I or E signal.

Errors when one attempt to record an impedance point failed

This failure is not fatal. The script resets the measurement settings and retries the measurement at the same frequency:

Vac too small The voltage signal is significantly smaller than the value entered in Setup. The script will increase the FRA’s signal output and try again.
Vac too big The voltage signal is significantly bigger than the value entered in Setup. The script will decrease the FRA’s signal output and try again.
Iac too big The AC current signal is outside the FRA’s range. The script will reset either the FRA sensitivity or the potentiostat’s current range.
Idc too big The DC current signal is outside the potentiostat’s range or the FRA’s common mode range. The script will reset either the FRA sensitivity or the potentiostat’s current range.