Generic Stegmann Feedback Selection

The Generic Brush, Generic Resolver, Generic Pulse, and Generic Encoder selections allow you to run a wide variety of motors using very basic feedback types. While the Stegmann Hiperface encoders are a specific brand and type of serial encoders, they are used by a wide range of motor manufacturers. To accommodate the many types of motors using the Hiperface encoders, a generic approach was appropriate.

There is specific manufacturer support for some motors with Hiperface encoders, such as Allen Bradley. The Allen Bradley support reads the encoder memory and sets up the motor for the run. In that sense it functions more like an Allen Bradley drive, and it will be quicker and easier to use than the Generic Stegmann selection.

The Generic Stegmann selection provides a general method of running motors with Hiperface encoder feedback in much the same way as the Generic Encoder selection. The user must enter certain timing information so that the TI-3000JX knows how to deal with the specific motor.

Setup

The FBK MFG key must be pressed until the top line of the display shows Generic Stegmann. The FBK TYPE key is then used to select the model of Hiperface encoder in use on the motor. The following encoders are supported under V3.1:

The Stegmann Hiperface SNS50/60 encoders are quite a bit different from the other Hiperface encoders. These encoders provide serial data lines, like other Hiperface encoders, but they do not provide absolute position information from the serial data. All position data is from the A and B (cosine and sine) channels. On power-up the encoder produces 1024 periods per revolution on the A and B channels. This will provide 4096 incremental counts/revolution.

The serial lines may be used to program the encoder to output an index pulse once per revolution. In this mode, the encoder can provide absolute position data (after it is indexed), and it works like any other incremental encoder with A, B, and Z channels. The index pulse uses the serial lines, so in this mode the serial channel can no longer be used for serial data. The encoder will remain in this mode until it is powered down. 

You should observe these precautions with SNS50/60 encoders:

1. Always power down the TI-3000JX before connecting or disconnecting the encoder.
2. After you have gone to DEBUG and indexed the encoder for the first time, it will no longer be able to communicate via serial lines. Do not change the selection from SNS50/60 after debugging.
3. If you do change selections for some reason, make sure that you power down the TI-3000JX when you re-select SNS50/60.

The TI-3000JX needs 3 pieces of information from the operator to run a motor with a Hiperface encoder:

1. The number of poles of the motor.
2. Whether encoder and armature phase directions are the same (D>S) or whether they are opposite (D>O). The forward direction for the Hiperface encoders is CW (looking at the shaft).
3. The encoder electrical angle when the rotor is locked using a +U –V lockup polarity (this can be accurately read from the display only after the first 2 items have been correctly entered).

This information can be found quickly and easily by a simple procedure. The information can then be entered into the TI-3000JX setup. All information of this type can be cataloged and simply entered into the TI-3000JX the next time a motor of the same type is used. The 10 step procedure is described below. On the page following the procedure, a form is shown that can be used to record the motor information during the procedure. You may wish to make copies of this page for recording your information.

1. Connect the encoder leads to the TI-3000JX encoder terminal block J1 in the manner suggested by the motor manufacturer. Use a Mitchell Electronics, Inc. test cable of one is available. Otherwise connect it as follows:
   
   
   
   
2. Power up the TI-3000JX and select Generic Stegmann by pressing the FBK MFG key. Then press the FBK TYPE key to select the Hiperface model that is used on your motor. When this selection has been made, press the DEBUG key to go into Debug Mode. The display will show ‘Debug’.
   
   If the message ‘Stegmann error’ appears, then there is a problem which could mean several things such as: 1) There is a wiring problem in connecting the encoder to the TI-3000JX, 2) The power supply to the encoder is insufficient and you should use the TI-5104 Adapter Module, or 3) There is a problem with the encoder or encoder wiring inside the motor. There may be other problems as well which the TI-5000JX with Stegmann support would be helpful in isolating.
   
   If the message ‘Stegmann ID XX’ is displayed (where XX is some Hiperface ID number), it means that the displayed ID has been read from the encoder, and it is not the correct ID for the encoder model that you have selected. This could mean several things such as: 1) You have made the wrong encoder selection or 2) There is a problem with the encoder. Again, the TI-5000JX with Stegmann support may be helpful in isolating the problem.
   
   If either of these messages appears, press the STOP key and correct the problem before continuing.
   
   For the SNS50/60 encoders, rotate the shaft 2 or 3 revolutions to index the encoder before moving to the next step. When the TI-3000JX begins displaying the angle, the encoder has been indexed.
   
   
3. With the armature disconnected from the amplifier, connect a low voltage (around 5 volts, preferably adjustable from a small bench power supply) with + to the U and - to the V armature leads (or +A, - B, or however they are designated). The motor should move to a position where it locks up.
   
   Note: If you do not have information on armature pinouts, make up your own assignments and proceed.
   
   
4. Slowly rotate the motor by hand through a full revolution and note the number of times it locks up in one rotation. Multiply that number by 2 and enter it as the number of poles on the worksheet.
   
   
5. Visually note the lockup position. Turn off the power supply. While leaving the + power supply lead
   on U, move the - lead from V to W. Turn the power supply back on, and the motor should move a small amount either CW or CCW. Note this direction on the worksheet as the forward armature direction.
   
   
6. Most of the information is now available to enter into the TI-3000JX. Some of it must be entered at this time so that the lockup angle can be read correctly in later steps. Press the STOP key to exit Debug Mode. Then press the SETUP key, and a data entry screen will appear. The cursor will be on the field for the number of poles. It will read either 2 as the default or the last number entered. Each time the EDIT key is pressed, the number will increment to a new number of poles. After reading 36, it will return to 2. Press EDIT until it reads the number of poles indicated on the worksheet.
   
   With the correct number of poles showing, press the ENTER key, and the cursor will move to the direction field. This field begins with “D>” and ends with either ‘S’ or ‘O’. ‘S’ means that the encoder forward direction is the same as the armature phases. Conversely, an ‘O’ means that the encoder direction and armature phase direction are opposite. Each time the EDIT key is pressed, the display will toggle from ‘S’ to ‘O’ or vice versa. If in step 5 the armature forward direction was CW, the encoder and armature direction are the same. Press the EDIT key until the display shows D>S. If in step 5 the armature direction was found to be CCW, then it is opposite the encoder direction. Press the EDIT key until the display shows D>O. Record on the worksheet the setting that makes the encoder angle increase when the motor is rotated in the forward direction. Press the SETUP key to exit Setup Mode.
   
   
7. Press the DEBUG key to go into Debug Mode (for SNS50/60 encoders, again rotate 2 or 3 revolutions to index the encdoder). Apply a DC voltage + to U and - to V. Move the motor through one rotation in the forward direction, and record each lockup angle on the worksheet. There should be one lockup position for each pole pair. For instance, a 2 pole motor will have 1 position, while an 8 pole will have 4 lockup positions. The angles displayed using the Generic Stegmann selection will be electrical angles, so each lockup position should show approximately the same angle (normally no more than +/- 5 degrees different). If the angles are significantly different, check to see that you have entered the correct number of poles for the motor.
   
   
8. The remaining information is now available to enter into the TI-3000JX. As in step 5, press the STOP key and then the SETUP key to enter Setup Mode. The cursor will be on the field for the number of poles. Press the ENTER key and the cursor will advance to the direction field, and then to the Angle field. The Angle field will read either 000 as the default, or it will read the last angle entered. Key in 3 digits to enter the number of degrees recorded on the worksheet in the lockup data. After the 3rd digit is entered, the cursor will jump back to the Poles field.
   
   Note: Angles must be entered as 3 digits with leading zeroes if necessary. For example, 30 degrees
   must be entered as 030.
   
   Review the number of poles, counts/rev, direction, and angle data showing on the display. If any are not correct, use the ENTER key to move to that field and correct the data as described above. When all of the data is correct, press the SETUP key to exit the Generic Stegmann setup menu. The 2nd line of the display will show the information as follows:
   
   Pp Dd Addd L+-*    where: p = number of poles
                                              d = Direction, S or O
                                              ddd = lockup angle

For instance, if it is a 4 pole motor with the same armature forward direction as encoder direction that locks up at 150 degrees, the display will show: P4 DS A150 L+-*

Debugging

Debugging is a quick and essential step that must be accomplished before trying to run the motor. If there are any problems in the setup, correct debugging should find them. If the correct setup has not been verified by debugging, there is nothing to be accomplished by attempting to run the motor. Section 2.2.3 provides general information about debugging the TI-3000JX setup. You will want to be familiar with that material.

When you believe that the TI-3000JX is properly set up (as described in the previous section), perform the following steps to debug the setup:

1. Press the DEBUG key to enter Debug mode (for SNS50/60 encoders, rotate the shaft 2 or 3 revolutions to index the encoder).
   
   
2. Rotate the shaft and verify that the encoder angle moves smoothly through the entire range of angles from 0 to 359 degrees. It should move through that range the same number of times as the number of motor pole pairs (2 poles – 1 time, 8 poles – 4 times, etc.).
   
   
3. Verify that the armature leads are not connected to the drive. From the lockup power supply, connect the + lead to the U phase and the – lead to the V phase.
   
   
4. Switch on the lockup power supply. The angle reading should be very close to the lockup angle that you recorded on your worksheet. For motor poles greater than 2, there will be multiple lockup positions, but the angles should be the same within 2 or 3 degrees.
   
   
5. On the TI-3000JX display, you should see V = H and W = L. When you wiggle the shaft slightly, you should see U change or toggle between H and L. This is very important. If this does not happen, the motor cannot run properly, and you have a mistake in your setup that must be corrected.
   
   
6. Switch off the lockup power supply and move the – lead from phase V to phase W. This will provide a valuable cross-check for verifying proper operation.
   
   
7. Switch on the power supply and note which way the motor jogs. This should agree with the forward direction you noted on your worksheet.
   
   
8. Read the angle from the TI-3000JX display. If it is greater than the angle you read with the +U –V lockup (providing the angle did not move through zero), the encoder and armature rotation are the same and your direction display should show D>S. If the displayed angle is less than the angle you read with the +U –V lockup (providing the angle did not move through zero), the encoder and armature rotation are opposite, and your direction display should be D>O.
   
   
9. On the TI-3000JX display, you should see U = L and V = H. When you wiggle the shaft slightly, you should see W change or toggle between H and L. This is very important. If this does not happen, the motor cannot run properly, and you have a mistake in your setup that must be corrected.

Those specific setup checks should help insure that your Stegmann encoder motor will run correctly. For more general information on debugging your setup, see Section 2.2.3.

Running

For SNS50/60 encoders, you must press the RUN key while in Debug after indexing the encoder. You cannot go directly from the Stop state to the Run state.

Encoders with 5 volt square wave signals usually do not have noise problems, although some of the suggestions below (such as the case ground line with the power leads) are good advice for running any motor.

Stegmann Hiperface encoders use 1 V p-p voltage levels for the counting signals and therefore are more likely to have noise problems due to the low level signals. Using the TI-5104 Indramat Adapter module with these encoders can reduce noise problems. The differential amplifiers in the module tend to cancel the noise and amplify the desired signal to a higher level.

Many of the Stegmann Hiperface encoders require a power supply voltage of 7 – 12 VDC. The TI-5104 module provides that additional advantage of providing 8 VDC power. You should verify the correct voltage on your encoder, but it appears that even the 5V Hiperface encoders will accept up to 12 VDC. This means that the TI-5104 should be usable with all Hiperface encoders.

Here are some further points to help reduce noise:

1. Make sure that you have a ground continuous from the motor body to the body of the drive. The drive cable has a G pin on it that goes to the drive body. The motor usually has a ground pin on the power connector. Make sure you make that connection.
   
   
2. Sometimes a shielded cable for the armature leads will help.
   
   
3. Sometimes a shielded cable for the encoder leads will help.
   
   
4. Try to keep the power leads and feedback leads as far apart as possible.