1 master value rail/slave cascade, Master value rail/slave cascade 9, 17 function library – Lenze 8400 HighLine User Manual

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Lenze · 8400 HighLine · Referenzhandbuch · DMS 10.0 EN · 06/2014 · TD05/TD14

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17

Function library

17.1

Function blocks

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17.1.73.1 Master value rail/slave cascade

If there is only one master speed that is transmitted to all slave drives involved, e.g. via system bus

(CAN), it is called master value rail.
If a slave drive takes over the master value generation for the following slave, it is called slave

cascade.

[17-35] Example: Master value rail/slave cascade

17.1.73.2 Setpoint conditioning with stretch factor and gearbox factor

Stretch factor
The stretch factor is required for the "speed synchronism via master value cascade" mode. It defines

the ratio the slave drive is to be running with regard to its master value.

• The stretch factor evaluates the setpoint at the nSet_v input.
• The stretch factor must be selected via the wGainNum and wGainDenom inputs in the form of

numerators and denominators.

• The result is provided at the nSetGain_v output.

• Scaling: 16384 ≡ 15000 rpm

• If the stretch factor is 1 and the gearbox factors are selected correctly, the circumferential

speeds of the rolls for master and slave 1 are identical in the example shown in the illustration

[17-35]

.

Master value rail

Slave cascade

Master value encoder

v

i

Slave

Master/Slave

d

v

d

v

d

v

R1

R2

R3

1

2

3

i

1

i

2

3

Ž



System bus

Œ

8400

8400

nSetGain_v

nSet_v wGainNum

wGainDenom

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