This is some information that I think some users will find helpful. I was trying to learn more about the Dmm DYN 4 tuning, for use with the Masso. After speaking with the guys at Dmm, they sent me the following information, which I will pass on with their permission.
Electronic gear reduction parameter. GEAR_NUM x 4 = number of pulses needed to rotate motor 1 revolution. For example, if GEAR_NUM is set to 1,000, then 4,000 pulses are needed to rotate motor 1 revolution. Generally, GEAR_NUM should be set as high as possible for best resolution and smoothness. But GEAR_NUM also affects max motor speed depending on CNC controller pulse frequency so this should be balanced with the speed requirement: Example 1: Controller max pulse frequency = 100kHz. Machine target speed = 500IPM. Motor direct drive on 5mm pitch ball screw. 500inch/min / 5mm/rev = 2540rev/min from motor. 2540rpm = 42.33rev/second. 100kHz = 100,000pulse/sec / 42.33rev/sec = 2362pulse/rev. So set GEAR_NUM to 590. Note 1. The GEAR_NUM parameter is only used to calculate the command from the CNC controller. The servo drive and servo motor always maintains position at 16-bit (65,536points/rev) resolution Note 2. GEAR_NUM setting should allow at least twice the resolution of machine accuracy target. See example 2 below. Example 2. If motor is driving a rack and pinion axis with a 2:1 reduction and 25mm pinion diameter. Target accuracy = 0.05mm. 25mm diameter pinion = 157mm circumference (linear travel per pinion revolution). 157/2 = 78.5mm linear travel per motor revolution. Twice target accuracy = 0.025mm. 78.5/0.025=3,140points/rev. So set GEAR_NUM to at least 785.
The LINE_NUM is the same as the GEAR_NUM but it controls the resolution of the encoder OUTPUT. The GEAR_NUM is the pulse ratio of the pulse/dir command input from the controller. The LINE_NUM is the encoder output resolution from JP5 connector. The MASSO doesn't read the encoder from the drive so this parameter is not used.
Servo direction, if a servo rotation needs to be reversed (as in a slave situation), the Dir+, and Dir- can be reversed on one of the drives without damage. The Masso also has an option to do this in the Slave axis window.
Electronic gear reduction parameter. GEAR_NUM x 4 = number of pulses needed to rotate motor 1 revolution. For example, if GEAR_NUM is set to 1,000, then 4,000 pulses are needed to rotate motor 1 revolution. Generally, GEAR_NUM should be set as high as possible for best resolution and smoothness. But GEAR_NUM also affects max motor speed depending on CNC controller pulse frequency so this should be balanced with the speed requirement: Example 1: Controller max pulse frequency = 100kHz. Machine target speed = 500IPM. Motor direct drive on 5mm pitch ball screw. 500inch/min / 5mm/rev = 2540rev/min from motor. 2540rpm = 42.33rev/second. 100kHz = 100,000pulse/sec / 42.33rev/sec = 2362pulse/rev. So set GEAR_NUM to 590. Note 1. The GEAR_NUM parameter is only used to calculate the command from the CNC controller. The servo drive and servo motor always maintains position at 16-bit (65,536points/rev) resolution Note 2. GEAR_NUM setting should allow at least twice the resolution of machine accuracy target. See example 2 below. Example 2. If motor is driving a rack and pinion axis with a 2:1 reduction and 25mm pinion diameter. Target accuracy = 0.05mm. 25mm diameter pinion = 157mm circumference (linear travel per pinion revolution). 157/2 = 78.5mm linear travel per motor revolution. Twice target accuracy = 0.025mm. 78.5/0.025=3,140points/rev. So set GEAR_NUM to at least 785.
The LINE_NUM is the same as the GEAR_NUM but it controls the resolution of the encoder OUTPUT. The GEAR_NUM is the pulse ratio of the pulse/dir command input from the controller. The LINE_NUM is the encoder output resolution from JP5 connector. The MASSO doesn't read the encoder from the drive so this parameter is not used.
Servo direction, if a servo rotation needs to be reversed (as in a slave situation), the Dir+, and Dir- can be reversed on one of the drives without damage. The Masso also has an option to do this in the Slave axis window.
