# PULS & SPED for Controlling Servo Drive

## 7 posts in this topic

Hi All,

Need some help on Cx-Programmer.

I've been using CP1L to control Panasonic Servo Drive and Servo Motor by using instruction PULS & SPED.

Panasonic Servo Motor model number is: MDMA502P1G, with Servo Drive type is: MFDDTB3A2

The questions are:

1. In my opinion for PLS is the instruction to ask the servo motor rotate by how many degree by sending pulse. and SPED is the speed of servo motor, was it correct?

2. One rotation should be 2500 pulse per rotation according to servo motor specification, but why I'm sending 1.525 to PLS instruction means 1 rotation (360degree)?

3. What is the maximum speed for this servo motor? Should be 2000r/min (based on photos at Servo Motor) * 2500 pulse per rotation while SPED units for F is pps, means maximum speed is around

83.333pps?

Here i attach the name plate on the AC Servo Motor.

Thx.

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First of all I recommend you use the PLS2[887] instruction. This allows modification of the accel/decel rate, target frequency [max. speed] number of pulses and whether movement is relative or absolute.

In your  application a 2000 rpm motor with 2500 pulses/rev would require [2000 x 2500]/60 = 83333 pulses/second to achieve max. speed.

You cannot send fractional values for pulse outputs [you mention 1.525].

My 2 cents.

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Dear BITS N BYTES,

Thx for suggesting me using PLS2 instruction, I will use it in the future, so for now i will try using PLS & SPED instruction for this case since i modify the existing machine.

Sorry i mean i send 1525 pulse (not 1.525) to PLS instruction.

Before that, I'm new to servo drive and servo motor with its application to PLC.

So why I'm sending 1525 pulse means 1 rotation in the PLS instruction? How to i determine hw many pulse for 1 rotation.

I got 1525 by testing one by one. I'm sure there is a better way to determine the pulse for PLS instruction.

So is it correct that the F in the SPED instruction is 83.333 for the max speed?

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PLS sets the number of pulses you want to send to the drive.

If you want to rotate the motor 1 revolution and the drive and motor is set up correctly so that 2500 pulses = 1 revolution use 2500 in PLS.

SPED sets the target frequency [pulse rate] used to output the number of pulses set by the PLS instruction.

If you want to rotate the motor at full speed of 2000 rpm then use 83333 for the target frequency in the SPED instruction.

Read the relevant section in the manual W451-E1-03, this has examples of how to implement PLS+SPED on page 730.

Edited by BITS N BYTES

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but why right now if I’m sending 2500 for PLS the motor rotate almost 2 rotation (like 1 3/4 rotation for 2500pulse)?

do you have any idea where should i check?

I’m using cp1l-m30dt-d for this case.

thx before

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do you have any idea where should i check?

If you are sure PLC program is configured correctly with PLC and SPED then the problem has to be in the Servo Drive parameters.

Can't help you there as I am unfamiliar with the Panasonic servo products.

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21 hours ago, budiman said:

but why right now if I’m sending 2500 for PLS the motor rotate almost 2 rotation (like 1 3/4 rotation for 2500pulse)?

do you have any idea where should i check?

I’m using cp1l-m30dt-d for this case.

thx before

Check scaling in the servo drive parameters on the pulse input side.  There may be something like input numerator / input denominator so that:

Motor movement = pulses in * (input numerator/input denominator).