F07088 — Units changeover: Parameter limit violation due to units changeover

F07088 reports that a changeover of units was initiated and that this changeover resulted in a violation of a parameter limit. During the changeover the drive adapts parameter values to the newly selected system of units; where an adaptation would leave a value outside its limits, the drive rounds the value back inside the limit and signals the adaptation with this fault. The message value names the parameter concerned, and all adapted parameters are listed in r9451.

• A changeover of units was initiated, and the changeover resulted in a violation of a parameter limit.
• When a parameter is rounded off corresponding to its decimal places, the rounding can violate the steady-state minimum limit or the maximum limit of the parameter.
• Inaccuracies of the data type "FloatingPoint": in these cases a value that violates the minimum limit is rounded up, and a value that violates the maximum limit is rounded down, so that the stored value stays inside the limits.

1. Open r9451 (Units changeover adapted parameters) — this diagnostics parameter displays all parameters whose value had to be adapted by the units changeover.
2. Check the adapted parameter values and correct them if required.

• The message value identifies the affected parameter: the drive stores "Parameter: %1", i.e. the number of the parameter concerned.
• The fault value is stored in r0949 and is to be interpreted as a decimal number. For this fault it points to the diagnostics parameter r9451, which displays all parameters whose value had to be adapted.

• r0949 (Fault value) — read the fault value of F07088 here and interpret it as a decimal number; it refers you to the diagnostics for the adapted parameters.
• r9451 (Units changeover adapted parameters) — displays all parameters whose value had to be adapted by the units changeover; work through this list to check and, if required, correct the adapted values.
• p0100 (IEC/NEMA Standards) — selects the IEC/NEMA standard; a unit-related setting the manual references for this fault.
• p0349 (System of units motor equivalent circuit diagram data) — selects the system of units for the motor equivalent circuit diagram data; a unit-related setting referenced for this fault.
• p0505 (Selecting the system of units) — the system of units is selected here; changing the unit system is what initiates the changeover to which this fault refers.
• p0595 (Technological unit selection) — selects the technological units; a unit-related setting referenced for this fault.

This fault triggers no automatic response: the drive does not change its operating state. Work through the checks above first, then acknowledge the fault immediately — switching the drive off and on again is not necessary. Acknowledge it from the operator panel or in the commissioning tool as usual; the fault is then cleared, and the drive keeps the adapted parameter values until you change them.