When using the PID (proportional integral derivative) function in Yaskawa drives, it may be desired to set an upper limit and/or lower limit to keep the PID output from exceeding above or dropping below a fixed level. The PID Output (monitor U5-03) corresponds to the output frequency and is displayed as a percentage of the maximum frequency (60hz default).

• Parameter b5-06 sets the PID Output Limit (upper). The default setting is 100%.
• Parameter b5-34 sets the PID Output Lower Limit. The default setting is 0%.

Note: A PID output limit is ONLY applicable when PID mode is enabled (b5-01 ≠ 1).

PID Output Limit (Upper)

Set parameter b5-06 to a desired PID output limit (upper) as a percentage of the maximum frequency. This will have an effect when the PID Output (monitor U5-03) is either positive or negative (when b5-11 =1).

• For example, set b5-06 = 90%. In PID mode, the maximum output frequency will be limited to 54Hz, which is 90% of 60Hz. If b5-11 = 1, this limit will apply in both forward and reverse directions.

PID Output Lower Limit

Set parameter b5-34 to a desired PID output lower limit as a percentage of the maximum frequency. This limit applies to a positive PID output (monitor U5-03) ONLY and therefore will limit the motor direction to forward, regardless of the b5-11 setting. A negative value set in b5-34 will not have any effect.

• For example, set b5-34 = 25%. In PID mode, the minimum output frequency will be limited to 15Hz, which is 25% of 60Hz. The drive will never run in the reverse direction, even if b5-11 = 1.

Note: The output frequency will be limited to the larger of b5-34 (PID Output Lower Limit), d2-02 (Lower Limit), or b5-91 (EZ Sleep Minimum Speed) values if applicable.

PID Offset

Set parameter b5-07 to the desired PID output offset as a percentage of the maximum frequency. This will "shift" the maximum and minimum PID output (monitor U5-03) levels.

• For example, set b5-07 = 25%. In PID mode with b5-11 = 1 and assuming b5-06 = 100% and b5-34 = 0%, the PID output will now be limited to -75% and 125%. Therefore, the output frequency will be limited to 45Hz (-75% in reverse) and 60Hz (125% in forward).

If desiring both a negative PID output limit and a positive PID output limit, follow the steps below.

1. Set b5-06 (PID Output Limit) to half of the sum of the desired range value. In this case, b5-06 is being treated in the drive as an absolute value +/-%.
   • For example, if desiring a 75% to -10% PID output range, set b5-06 = 42.5%. Adding 75% and (-)10% equals 85%. Dividing 85% by 2 equals 42.5%.
2. Set b5-07 to an offset to add to the desired upper and lower limit.
   • For example, set b5-07 = 32.5% to allow a 75% upper limit and -10% lower limit for the PID output. Subtracting 42.5% (b5-06) from 75% equals 32.5%.
     • 32.5% offset + 42.5% (output limit) = 75% (upper limit)
     • 32.5% offset - 42.5% (output limit) = -10% (lower limit)
3. Verify or set b5-34 to 0% for the PID output lower limit.

Note: Monitor U5-03 can be used to view the PID Output while in operations.