假设要裁切的长度为S，主动辊的周长为L，主辊转过的圈数N（或者说角度），则S=LN，这是一个线性方程，也即S和N成正比，假设减带机齿轮的变比为K，则可求出S和电机转过圈数X，S=L＊X/K。此式说明S和X仍为一个线性方程，为此要取得需要的长度S，只需控制住电机转过的圈数。在原系统中采用变频器、PLC、编码器和高速计数模块来组成控制系统，其中PLC给定值（长度对应的脉冲量）送入变频器驱动电机运转，

SIEMENS 6FX1-138-6BB01  6FX11386BB01
SIEMENS 6FM1-726-3BA00  6FM17263BA00
SIEMENS 6FM1-470-3BA25  6FM14703BA25
SIEMENS 6FM1-470-3BA20  6FM14703BA20
SIEMENS 6ES5-955-5LB11  6ES59555LB11
SIEMENS 6DD1-661-0AB1  6DD16610AB1
SIEMENS 6AV7-614-0AB12-0BJ0  6AV76140AB120BJ0
SIEMENS 1PH7107-2HD03-0BA3  1PH71072HD030BA3
SIEMENS 1GG5-162-0WX40-6HV3-Z  1GG51620WX406HV3
SICK OPTIC ELECTRONIC LMS-200-S60  LMS200S60
SCHWEITZER ENGINEERING SEL-121F-X-4256MHNB  SEL121FX4256MHNB
RELIANCE ELECTRIC FLEXPAX3000  FLEXPAX3000
RELIANCE ELECTRIC DDM-019X  DDM019X
RELIANCE ELECTRIC B/M-60001-1  BM600011
RELIANCE ELECTRIC B/M-60001  BM60001
RELIANCE ELECTRIC 86466-87T  8646687T
RELIANCE ELECTRIC 86466-87R  8646687R
RELIANCE ELECTRIC 57C-43   57C43
RELIANCE ELECTRIC 57C-435  57C435
RELIANCE ELECTRIC 45C-203  45C203
RELIANCE ELECTRIC 10P8171  10P8171
RELIANCE ELECTRIC 0-57435-G  057435G
RELIANCE ELECTRIC 0-52837  052837
RELIANCE ELECTRIC 0-52501-1  0525011
PANASONIC YB-020UDD  YB020UDD
NEMATRON CORP -8L6-HS1-850  8L6HS1850
MODICON MM-PMC3-100  MMPMC3100
MODICON MM-PMA2-400C  MMPMA2400C
MODICON I646-4  I6464
MODICON AS-509P-007  AS509P007
MODICON 141-MMS-425-01  141MMS42501
MIYACHI IS-471B  IS471B
MITSUBISHI HALP15K24BK  HALP15K24BK
MITSUBISHI FRZ220-22.0K  FRZ220220K
MITSUBISHI FR-SF-2-22K  FRSF222K
MITSUBISHI A2U-CPU-S1  A2UC1
MICROSWITCH 82114930-50  8211493050
MICROSTAR LABORATORIES DAP3200A/415  DAP3200A415
MEASUREX 51403299-200  51403299200
MEASUREX 51402755-100  51402755100
MEASUREX 09437300  09437300
LAMBDA LK343A  LK343A
KRS MAFFEI 5089880  5089880
KOLLEN IND BDS4A-103J-0001-202A2  BDS4A103J0001202
KAIJO ELECTRIC 8801B-MR  8801BMR
JOSLYN CLARK 5DP9-9009-11  5DP9900911
JOHNSON CONTROLS NU-NCM300-1  NUNCM3001
ISSC 621-0022-VRC  6210022VRC
INDRAMAT TDM-1.2-50-300-W1-115  TDM1250300W1115
INDRAMAT MDD-112C-N-030-N2M-130PB0  MDD11030N2M1A
INDRAMAT MDD090C-N-030-N2L-110PB0  MDD09030N2L1A
INDRAMAT MDD-090B-N-020-N2L-110PB0  MDD090BN020N2L11
INDRAMAT MAC112C-0-ED-4-C/130-A-1/WI520LV/S005  MAC112C0ED4C1303
INDRAMAT 2AD132D-B350B1AS01/S007  2AD132DB350B1AS0
HONEYWELL R7510-B1003-4  R7510B10034
HONEYWELL R7510-B1003-2  R7510B10032
HOFFMAN ENCLOSURES AFMSC30248SS  AFMSC30248SS
HOFFMAN ENCLOSURES AFMSC20206SS  AFMSC20206SS
GOULDS PUMP AV2V50100D  AV2V50100D
GIDDINGS & LEWIS M.1016.9428-R9  M10169428R9
GIDDINGS & LEWIS 502-03944-00  5020394400
GENERAL ELECTRIC M60-K03-HLH-F8L-H6L-M5C-PXX-UXX-WRH  M60K03HLHF8LH6LM
GENERAL ELECTRIC IC2800Y122A2K  IC2800Y122A2K
GENERAL ELECTRIC IC2800Y122A2B  IC2800Y122A2B
GENERAL ELECTRIC DS3810CLCB  DS3810CLCB
GENERAL ELECTRIC DS3800HPBC  DS3800HPBC
GENERAL ELECTRIC DS200SHVMG1AFE  DS200SHVMG1AFE
GENERAL ELECTRIC 5CD164MA019A002  5CD164MA019A002
GENERAL ELECTRIC 531X132APGACG1  531X132APGACG1
GENERAL ELECTRIC 145D4738G1  145D4738G1
GENERAL ELECTRIC 115D2291G2  115D2291G2
GE FANUC IC800SSI107D2  IC800SSI107D2
GE FANUC IC800SSD228S1  IC800SSD228S1
GE FANUC IC697CPU771  IC697CPU771
GE FANUC IC3600AIAD1  IC3600AIAD1
GE FANUC 44A391796-G01  44A391796G01
FOXBORO P0961FR  P0961FR
FOXBORO P0926CP  P0926CP
FISHER ROSEMOUNT DH6005X1-DA1  DH6005X1DA1
FISHER ROSEMOUNT CL6011X1-BA1  CL6011X1BA1
FISHER ROSEMOUNT CL6003X1-A3  CL6003X1A3
FISHER ROSEMOUNT CL6003X1  CL6003X1
FISHER ROSEMOUNT CL6003  CL6003
FANUC A20B-8001-0120  A20B80010120
FANUC A20B-1001-0770  A20B10010770
FANUC A06B-6102-H222  A06B6102H222
FANUC A06B-6050-H006  A06B6050H006
FANUC A06B-6047-H104  A06B6047H104
FANUC A06B-6045-H005  A06B6045H005
FANUC A06B-0583-B374  A06B0583B374
FANUC A06B-0313-B202  A06B0313B202
EUROTHERM DRIVES 591P/0725/500/0040/UK/ARM/0/115/0  591P07255000040U
ELECTRO CRAFT DDM-005X  DDM005X
DOMINO 37711  37711
DOLAN JENNER SS400-10082/RECEIVER  SS40010082RECEIV
CUTLER HAMMER SV9NCL  SV9NCL
CUTLER HAMMER ND312T33W  ND312T33W
CUTLER HAMMER HNB31200T  HNB31200T
CUTLER HAMMER HLDB3600FT33W  HLDB3600FT33W
CINCINNATI MILACRON 6SC6101  6SC6101
CATEL 152499-5  1524995
BOSCH 1070077958-200  1070077958200
BOSCH 1070071221-102  1070071221102
BOSCH 1070071212-106  1070071212106
BOSCH 1070062309-502  1070062309502
BOSCH 050881-403  050881403
BAUMULLER 21-30/60-31-031  21306031031
BALDOR MT-7030-ALYDN  MT7030ALYDN
BAILEY CONTROLS NMFC-05  NMFC05
BAILEY CONTROLS INNPM-11  INNPM11
AUTOMATED LOGIC M01010PNX  M01010PNX
ATLAS COPCO LTD27SR005-RE  LTD27SR005RE
ASEA BROWN BOVERI YXT115B  YXT115B
ASEA BROWN BOVERI 926A416G13  926A416G13
ASEA BROWN BOVERI 923A357G05  923A357G05
ASEA BROWN BOVERI 7883A61G04  7883A61G04
ASEA BROWN BOVERI 6205BZ10100K  6205BZ10100K
ASEA BROWN BOVERI 58422177  58422177
ASEA BROWN BOVERI 57360001-A/5  57360001A5
ASEA BROWN BOVERI 57275847  57275847
APC PD40G6FK1-M  PD40G6FK1M
ANN ARBOR AAT2TTPIII850-SXTFT  AAT2TTPIII850SXT
AMK KU-BF1  KUBF1
ALLEN BRADLEY 803-A12  803A12
ALLEN BRADLEY 6160-T53  6160T53
ALLEN BRADLEY 505-M/A24487  505MA24487
ALLEN BRADLEY 2711-T12C6  2711T12C6
ALLEN BRADLEY 2711P-K15C4D1  2711PK15C4D1
ALLEN BRADLEY 2711P-B12C6D7  2711PB12C6D7
ALLEN BRADLEY 2711-K6C15L1  2711K6C15L1
ALLEN BRADLEY 1785-V30B  1785V30B
ALLEN BRADLEY 1785-L60B/E  1785L60BE
电机运转又带动编码器旋转产生脉冲，反馈回高速计数器送入PLC和原给定值比较，直到相等时停止电机的运行。实际使用中此系统虽然通过调整变频器的方式，引入、二加减速时间来减少电机的惯性，使电机在极慢速成爬行时停车。但此系统的精度仍不可能很高。其缺点：（1）编码器和电机不同轴、不是一体；（2）电机停车要用抱闸来刹车，而抱闸的快慢和力量对精度都将产生影响。而利用交流伺服系统后这两方面的缺点都克服了，从而得到了更高的精度。
ALLEN BRADLEY 1756-L55M16  1756L55M16
ALLEN BRADLEY 1756-L55M14  1756L55M14
ALLEN BRADLEY 1747-OCEDDBA  1747OCEDDBA
ALLEN BRADLEY 150-B35NBDA-J1  150B35NBDAJ1
ALLEN BRADLEY 150-B180NBD  150B180NBD
ALLEN BRADLEY 1398-DDM-030X  1398DDM030X
ALLEN BRADLEY 1398-DDM-019-DN  1398DDM019DN
ALLEN BRADLEY 1395-B65-D1-PZ  1395B65D1PZ
ALLEN BRADLEY 1395-B63-D1-PZ  1395B63D1PZ
ALLEN BRADLEY 1395B/S-B63-D1-PZ  1395BSB63D1PZ
ALLEN BRADLEY 1394-SJT10-A  1394SJT10A
ALLEN BRADLEY 1370A-RAOA7-0B1E  1370ARAOA70B1E
ALLEN BRADLEY 1336VT-B060-EOS-FA2-L3  1336VTB060EOSFA2
ALLEN BRADLEY 1336VT-B040-EAR-FA2-L3-S1  1336VTB040EARFA2
ALLEN BRADLEY 1336S-B100-AN-EN4  1336SB100ANEN4
ALLEN BRADLEY 1336S-B075-AA-EN-GM1  1336SB07 AENGM1
ALLEN BRADLEY 1336S-B075-AA-EN  1336SB07 AEN
ALLEN BRADLEY 1336S-B020-AA-EN4-GM1-HA2  1336SB020AAEN4GM
ALLEN BRADLEY 1336S-A020-AA-EN4-HA1-L6  1336SA020AAEN4HA
ALLEN BRADLEY 1327AA-BB-40-B  1327AABB40B
ALLEN BRADLEY 1326AB-B720E-21-MK7L  1326ABB720E21MK7
ALLEN BRADLEY 1326AB-B530E-21-Z13  1326ABB530E21Z13
ALLEN BRADLEY 1326AB-B3E-11  1326ABB3E11
ADEPT TECH 30340-40000  3034040000
ADEPT TECH 30340-20000  3034020000
AC POWER NPSA-103MU-E4CSA  NPSA103MUE4CSA
AC POWER NPSA-103MU-E1BS  NPSA103MUE1BS
URAY 082157-002  082157002