8.3 Parameter Settings for Fully-closed Loop Control8-218 Fully-closed Loop Control8.3.5 Electronic GearRefer to 4.4.3 Electronic Gear for the purpose of setting the electronic gear.The following formula is used to calculate the electronic gear ratio in fully-closed loop control.Note: Set Pn20E (numerator B) and Pn210 (denominator A) to integral values.The setting range is defined by 0.001 ≤ ≤ 4000.The following table shows the various external encoder sin wave pitches and the number of divisions. External Encoder Sine Wave Pitch and Number of DivisionsThe sine wave pitches and numbers of divisions for the external encoders are given in the following table.Calculate the electronic gear ratio with the values in the following table.∗1. If you use the encoder pulse output with these external encoders, the setting range of the encoder output resolution(Pn281) is restricted. For details, refer to 8.3.3 Setting Encoder Output Pulses (PAO, PBO, and PCO).∗2. Ask your Mitutoyo Corporation representative for details on this external encoder.∗3. This is the model of rotational external encoder.Refer to the manuals for the external encoder and serial converter unit for details on the sine wave pitch andthe number of divisions of the external encoder.ABPn210Pn20EExternal encoder sine wave pitch (value in the following table)Travel distance per reference unit × Number of divisions (value in the following table)Electronic gear ratio == =BAType ofExternalEncoderManufacturer External EncoderModelSineWavePitch[μm]Model of RelayDevice betweenSERVOPACK andExternal EncoderNum-ber ofDivi-sionsResolu-tionIncremen-talHeidenhain LIDA48 20 JZDP-D003-000-E 256 0.078 μmLIF48 4 JZDP-D003-000-E 256 0.016 μmRenishaw plc RGH22B 20 JZDP-D005-000-E 256 0.078 μmMagnescale Co., Ltd.SR75-LF*1 80 – 8192 0.0098μmSR75-MF 80 – 1024 0.078 μmSR85-LF*1 80 – 8192 0.0098μmSR85-MF 80 – 1024 0.078 μmSL700*1 , SL710 *1 ,SL720*1 , SL730 *1 800 PL101-RY 8192 0.0977μmAbsoluteHeidenhain LIC4100 20.48 EIB3391Y 4096 0.005 μmMitutoyo CorporationST781A/ST781AL 256 – 512 0.5 μmST782A/ST782AL 256 – 512 0.5 μmST783/ST783AL 51.2 – 512 0.1 μmST784/ST784AL 51.2 – 512 0.1 μmST788A/ST788AL 51.2 – 512 0.1 μmST789A/ST789AL*2 25.6 – 512 0.05 μmMagnescale Co., Ltd.SR77-LF*1 80 – 8192 0.0098μmSR77-MF 80 – 1024 0.078 μmSR87-LF*1 80 – 8192 0.0098μmSR87-MF 80 – 1024 0.078 μmRU77-4096ADF *3 – – 256 20 bitsRU77-4096AFFT01*3 – – 1024 22 bits
