张力的开环控制其实主要是电流控制，也就是转矩的控制，开环的张力控制用于很多场合，在我们的这一课中主要讲解用于轧钢行业的收卷机上的应用。
在上线的课程中我讲解了卷径计算，张力控制等模块的参数。在张力的开环上，我不做更多的介绍，我只是将轧机做收放卷所需要的参数列出来给大家做个参考。
下图是一份收卷的接线图，图上面反应了使用到的端子。
此主题相关图片如下：左卷电路图.jpg
为了方便大家我将整个调速器的菜单用超级终端捕捉了过来，在改过的参数后面都用―*‖号表示了出来，这是工程中已正在使用的组态。（只反应主要用到的参数，没用到的我都省略了）
DIGITAL DC DRIVE ISSUE:4.5 ..MENU LEVEL ....SETUP PARAMETERS ......SPECIAL BLOCKS ........DIAMETER CALC.
..........MIN DIAMETER [425 ] = 35.00 % *
..........MIN SPEED [426 ] = 5.00 %
..........RESET VALUE [462 ] = 65.00 % * ........TORQUE CALC.
..........TORQUE DEMAND [432 ] = 0.00 %
..........TENSION ENABLE [433 ] = DISABLED * ..........OVER WIND [434 ] = ENABLED ......FIELD CONTROL
........FIELD ENABLE [170 ] = ENABLED
........FLD CTRL MODE IS [209 ] = CURRENT CONTROL ........FLD VOLTAGE VARS
..........RATIO OUT/IN [210 ] = 90.0 % ..........FLD WEAK VARS
............FLD. WEAK ENABLE [174 ] = ENABLED * ............EMF LEAD [175 ] = 2.00 ............EMF LAG [176 ] = 40.00 ............EMF GAIN [177 ] = 0.30
............MIN FLD CURRENT [179 ] = 20.00 % * ............MAX VOLTS [178 ] = 100.00 % ............BEMF FBK LEAD [191 ] = 100 ............BEMF FBK LAG [192 ] = 100 ......CURRENT LOOP
........CUR.LIMIT/SCALER [15 ] = 100.00 % ........MAIN CURR. LIMIT [421 ] = 200.00 % ........PROP. GAIN [16 ] = 20.00 * ........INT. GAIN [17 ] = 10.00 * ........AUTOTUNE [18 ] = OFF ........FEED FORWARD [136 ] = 2.00
........DISCONTINUOUS [137 ] = 22.00 % * ........ADDITIONAL DEM [30 ] = 0.00 % ........BIPOLAR CLAMPS [90 ] = DISABLED
* ........REGEN MODE [201 ] = ENABLED ........POS. I CLAMP [301 ] = 100.00 %
........NEG. I CLAMP [48 ] = 0.00 % * ........I DMD. ISOLATE [119 ] = DISABLED ......SPEED LOOP
........PROP. GAIN [14 ] = 10.00 ........INT. TIME CONST. [13 ] = 0.500 SECS ........INT. DEFEAT [202 ] = OFF ........ENCODER SIGN [49 ] = POSITIVE
........SPEED FBK SELECT [47 ] = ANALOG TACH ........ADVANCED ......STANDSTILL
........STANDSTILL LOGIC [11 ] = ENABLED * ........ZERO THRESHOLD [12 ] = 2.00 % ........SOURCE TAG [306 ] = 89 ......SETPOINT SUM 1
........RATIO 1 [6 ] = 1.0000 ........RATIO 0 [208 ] = 1.0000 ........SIGN 1 [8 ] = POSITIVE
........SIGN 0 [292 ] = NEGATIVE * ........DIVIDER 1 [419 ] = 1.0000
........DIVIDER 0 [420 ] = 0.3500 * ....SYSTEM ......SOFTWARE ......CONFIGURE I/O
........CONFIGURE ENABLE [39 ] = DISABLED ........ANALOG INPUTS ..........ANIN 2 (A3)
............CALIBRATION [233 ] = 1.0000 ............MAX VALUE [234 ] = 15.00 % *
*