F07420 — Drive: Current setpoint filter natural frequency > Shannon frequency

F07420 is raised when the natural frequency of one of the current setpoint filters is greater than the Shannon frequency. The drive calculates the Shannon frequency as 0.5 / p0115[0], so the limit depends on the sampling time set in p0115[0]. The fault value in r0949 names, bit by bit, which filter is involved; the decoding differs between drive objects — the servo drive objects (SERVO, SERVO_AC, SERVO_I_AC) cover filters 1 to 10, while for A_INF and R_INF only filters 4, 5 and 7 are listed. Filters 5 to 10 belong to the extended current setpoint filter and are marked with r0108.21 in the decoding.

• One of the filter natural frequencies is greater than the Shannon frequency, which the drive calculates according to the formula 0.5 / p0115[0].

1. Read the fault value r0949 in binary and identify from the bit assignment which current setpoint filter is involved; bits 8 ... 15 of the fault value give the data set number (starting from zero).
2. Reduce the numerator or denominator natural frequency of the current setpoint filter involved (the parameters are assigned to the bits in the lists on this page).
3. Alternatively reduce the current controller sampling time p0115[0]; since the Shannon frequency is 0.5 / p0115[0], a shorter sampling time raises the limit.
4. Or switch out the filter involved with p1656.

The drive writes the fault value into r0949; interpret it binary. A set bit names the filter whose natural frequency is too high.

Drive objects SERVO, SERVO_AC, SERVO_I_AC:

• Bit 0: Filter 1 (p1658, p1660)
• Bit 1: Filter 2 (p1663, p1665)
• Bit 2: Filter 3 (p1668, p1670)
• Bit 3: Filter 4 (p1673, p1675)
• Bit 8 ... 15: Data set number (starting from zero)
• Bit 16: Filter 5 (p5202, p5204) — extended current setpoint filter (r0108.21)
• Bit 17: Filter 6 (p5207, p5209) — extended current setpoint filter (r0108.21)
• Bit 18: Filter 7 (p5212, p5214) — extended current setpoint filter (r0108.21)
• Bit 19: Filter 8 (p5217, p5219) — extended current setpoint filter (r0108.21)
• Bit 20: Filter 9 (p5222, p5224) — extended current setpoint filter (r0108.21)
• Bit 21: Filter 10 (p5227, p5229) — extended current setpoint filter (r0108.21)

Drive objects A_INF, R_INF:

• Bit 3: Filter 4 (p1673, p1675)
• Bit 16: Filter 5 (p5202, p5204)
• Bit 18: Filter 7 (p5212, p5214)

The parameter chapter names p1658 to p1675 as the denominator and numerator natural frequencies of the manipulated variable filters of the velocity controller; in this fault they are evaluated as current setpoint filters 1 to 4.

• r0949 — fault value; read it binary to find the affected filter and the data set number.
• p0115[0] — sampling time for supplementary functions; it determines the Shannon frequency (0.5 / p0115[0]) and is reduced as one remedy.
• p1658 / p1660 — denominator and numerator natural frequency of filter 1; lower the value concerned when bit 0 is set.
• p1663 / p1665 — filter 2, bit 1.
• p1668 / p1670 — filter 3, bit 2.
• p1673 / p1675 — filter 4, bit 3.
• p5202 / p5204 — current setpoint filter 5 (extended current setpoint filter, r0108.21), bit 16.
• p5207 / p5209 — current setpoint filter 6, bit 17.
• p5212 / p5214 — current setpoint filter 7, bit 18.
• p5217 / p5219 — current setpoint filter 8, bit 19.
• p5222 / p5224 — current setpoint filter 9, bit 20.
• p5227 / p5229 — current setpoint filter 10, bit 21.
• p1656 — activation of the manipulated variable filter of the velocity controller; use it to switch out the filter involved.
• r0108 — bit 21 of this parameter marks the extended current setpoint filter function module to which filters 5 to 10 belong.

The drive does not perform an automatic stop for this fault. Correct the filter natural frequency, the sampling time p0115[0] or the filter activation p1656 as described above, then acknowledge the fault — immediate acknowledgement is provided for, and a POWER ON also removes it — and restart the drive. While the parameterization is unchanged, the fault re-appears.