SureServo Drives and Motors Frequently Asked Questions
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Question:
Q: Can a 1 kW servo drive be powered with single phase?
Answer
A: Yes, it can.
FAQ ID: 1048
Question:
Q: When the home is reached, the output "Home completed" stays on, no matter what I do.. what is wrong?
Answer
A: Nothing wrong; the output turns on after an action of home search is done and the home position is found.. it will stay there always until the servo drive is powered off.
FAQ ID: 1049
Question:
Q: I need to move a load of 50 lb. What is the proper servo to utilize?
Answer
A: This information is not enough to answer that. The servo is sized based on the torque that the load requires. In order to determine the load torque, it is necessary to know the kinematics and the dynamics of the movement, that is, what is the speed profile the load will perform. Typically the motion is a trapezoidal profile with an acceleration ramp, a constant speed and then a deceleration ramp. The acceleration and decelerations will be data to calculate the torque required to move the mass (or inertia) of the load. The process torque and the friction torque is the additional torque to be calculated. This data will allow determining the torque along the time the motion is performed. Based on that data a motor can be sized. See appendix B of the user manual for details Automation Direct does not do sizing calculation. This should be done by the application engineer doing the control system.
FAQ ID: 1050
Question:
Q: Can I use MODBUS instead of the real digital inputs?
Answer
A: Yes, if the firmware of the servo drive is 2.105 or better. This firmware was available around August 2008.
Previous versions can do MODBUS but not the digital inputs. The most important parameters are P3-08 and P4-07. P3-08 is a mask that allows defining the physical 8 digital as real or alternatively as virtual, called virtual when used with MODBUS. P4-07 has a dual purpose. Each bit shows the status of the digital inputs but also allows commanding the inputs with MODBUS.
FAQ ID: 1052
Question:
Can I use these on electric vehicles?
Answer
AutomationDirect is a direct seller of automation and industrial control products such as PLCs, sensors, pushbuttons, AC drives/motors, enclosures, operator interfaces, and much more.
AutomationDirect is aware that many engineers and hobbyists are currently designing or converting vehicles from internal combustion engines to electric engines. Our current drive and motor products are intended to be used in industrial applications. As a result, AutomationDirect does not currently support or encourage the use of our products in electric vehicles. We apologize for this, and may revise this policy at a later date if more suitable equipment becomes available.
FAQ ID: 1072
Question:
What are the differences between steppers and servos.
Answer
Stepper motor control is the most cost-effective way to control a motion but it is an open loop. The accuracy is good if motor is properly sized and the price is reasonable. The torque decreases sharply when the speed increases. Also, the maximum speed for rapid moves and cutting moves are not as high as for servo control. The stepper motors need an amplifier to a train of pulses to deliver current to the windings. The controller is typically a PLC that will generate a speed trapezoidal profile to move the shaft angle from one position to other. There are also dedicated controllers called indexers that will do the same type of pulse generation. Or there are still more sophisticated controllers that can do coordinated motion of several axes.
Servo control uses feedback from an encoder to constantly monitor the motion exact position. Modern servos have constant torque over the speed range, and some field weakening only at the top speeds. Using the feedback signals, the control system can correct itself to achieve high speeds and perfect accuracy, even under very strenuous conditions. The modern servos have an amplifier with intelligence to allow several motion types, and can deliver torque, speed or position control with its own intelligence. In any case, a PLC is advisable when there is a need to execute some logic not possible to get from the internal algorithms.
FAQ ID: 1151
Question:
What are the fuses to be used with the servos?
Answer
Please see page 2-37 of the SureServo User Manual
FAQ ID: 1152
Question:
How do you program the servo for torque control?
Answer
- The servo drive can receive a +/- 10 Volt analog reference of torque, that you can scale for the proper range between +/- 300%, Set the parameter P1-01 as 3 or 5.
- You can use 3 preset values stored on the specific registers the servo drive and each one of them can be selected with 2 configured digital inputs.
- You can send set point of torque though MODBUS communications from a Master that talks MODBUS at rate of up to 115.2 kBaud.
More information can be found in chapter 5 of the SureServo User Manual
Application note AN-SERV-002 is one example of how to do it.
FAQ ID: 1153
Question:
How do you program the servo for positioning?
Answer
The servo drive can accept several positioning modes:
- Position Control (external command)
Pt mode (position terminal mode) with pulse and direction high speed pulses, quadrature pulses or clockwise and counter clockwise high speed pulses. In this modem, the servo drive is just an amplifier and the control is done by the controller generating pulses, for example, a CNC controller or a PLC module that could generate a trapezoidal profile. Set the parameter P1-01 as 0.
Position Control (internal command)
Pr mode (position with registers mode). In this mode, you can store up to 8 target positions, defined by revolutions (in one parameter register) and counts (in a consecutive parameter register) which can be absolute or incremental mode and each of them can be selected by 3 configured digital inputs. Set the parameter P1-01 as 1.
Additionally, you can send target set points though MODBUS communications from a Master that talks MODBUS at rate of up to 115.2 kBaud. Speeds, accelerations and decelerations can also be changed. Application note AN-SERV-007 is one example of this.
Variations of these basic position modes can also be done, with reduced features. More information is in chapter 5 of the SureServo User Manual
FAQ ID: 1155
Question:
ALE06 overload; what is the cause?
Answer
ALE06 is overload alarm. This is a case where the motor is taking more current than what the motor is rated for. In order to reset it, please solve the problem causing the overload and reset the drive by pushing the arrow keys simultaneously for 3 or more seconds or power off the drive or turn on a digital ipout configured as Alarm Reset There are several causes of this alarm, but the most important ones are:
6.1 - The motor has a brake and the brake has not been released. The way to release the brake is to apply 24 Volt though a relay with the help ofthe yellow and orange wires on the power cable. Polarity is not important.
6.2- The motor is undersized for the operation. The motor torque is proportional to the current of the motor. If more torque than the motor can deliver is demanded, the motor will request more current to the servo drive and this will cause the trip and the failure.
6-3 - The motor tuning has been set too sharp. Re-tune the servo to aslightly sloppy response.
FAQ ID: 1156
Question:
ALE02 undervoltage.what is the cause?
Answer
ALE02 undervoltage - Be sure that there is voltage (200 to 240 Volt AC) between L1 and L2. Check the voltage with a multimeter... it could be the lack of control power or a fuse is blown in that circuit.
FAQ ID: 1157
Question:
How to jump from digit to digit when using P3-08 and setting FF03?
Answer
Purpose is to set FF13 in P3-08. When the drive is powered up, please press the MODE key to go to parameter mode. It will show up P0-00. Press 3 times to go to P4-00. Use the DOWN arrow key to go to P3-08. Press the ENTER key. It will show up the content of P3-08. Let us say that shows 0. Use the UP arrow to go to 3 on the least significant digit. Use the NEXT key to move the cursor to the left. Use the UP arrow to go to 1 on the second least significant digit. Use the NEXT key to move the cursor to the left. Use the UP arrow to go to F on the next left digit. Use the NEXT key to move the cursor to the left. Use the UP arrow to go to F on the next left digit.
FAQ ID: 1158
Question:
The power terminals are difficult to wire. How this is done?
Answer
The power terminals are screw less terminals. The drive is supplied with a plastic tool to allow the easy insertion or the removal of the wires, as shown on the picture attached.
Wiring picture
FAQ ID: 1159
Question:
How can I connect the encoder output of the SureServo to the inputs of a CTRIO module?
Answer
The encoder output of the SureServo is line-driver ( 5V TTL). It won't work directly to the CTRIO or CTRIO2 modules.
You would need to use a High Speed Optical Isolators, like the FC-ISO-C or the FC-ISO-D
Host Engineering does also make an adapter board CTRIO-TTLANNEX that will allow you to connect a TTL signal to the CTRIO2. Please contact Host Engineering, Inc at "support@hosteng.com"
FAQ ID: 1200
Question:
What is minimum bend radius for the cables?
Answer
Unless specified elsewhere the rule of thumb is to not exceed a bend radius of less than 10 times the diameter of the cable.
FAQ ID: 1342
Question:
How do I connect my PC to SureServo?
Answer
SureServo amplifiers talk serial Modbus over RS232 or RS422/485 through the IEEE1394 (Firewire) connector.
Use either of the following methods to talk to the drive from your PC:
RS232: connect USB-RS232 to SVC-PCCFG-CBL (DB9 to IEEE1394 connectors)
RS485: connect USB-485M to SVC-485RJ12-CBL-2 (RJ12 to IEEE1394) or SVC-485CFG-CBL-2 (RJ45 to IEEE1394). [The USB-485M can accept either RJ12 or RJ45 connectors.]
FAQ ID: 1582