Allen Bradley (Reliance, Electrocraft) Motors

Overview

AB Series F, H, N, S, and Y use Renco incremental encoders, so please see that section for details. These motors may also be Reliance or Electrocraft brand depending upon their age. Refer to the Renco section for more information. The H series is known to sometimes use Stegmann Hiperface encoders.

The Reliance B and P series motors use Ono Sokki (or equivalent) incremental encoders with commutation signals.

AB MPS, MPL, MPF, 1326AB and 8720 motors use resolvers, incremental encoder, and Stegmann Hiperface encoders. Refer to the resolver and incremental encoder manual sections for more information. Refer to this section and the Stegmann section for more information on testing motors with the Stegmann Hiperface encoders. These encoders include memory, and Allen Bradley motors utilize this memory area for motor parameters including alignment information. This section will focus on the memory support for these motors.

 

Types Supported

The following lists show the Allen Bradley motors with their corresponding Stegmann Hiperface encoders that are currently supported by the TI-5000JX, along with test cable possibilities. Please check the current PDF catalog file and price list files for a complete listing of all cables supporting Allen Bradley motors.

This list includes Allen Bradley motors using Stegmann Hiperface encoders.

 

Note 1: Generic means a cable that connects directly to the encoder and works regardless of the type of motor. 

Note 2: The first count is the number of counts/rev for the incremental signals, the second is the number of counts/rev for the absolute serial position count, and the last count is the number of revolutions that can be counted (for multi-turn encoders only).

In addition to the above encoders, a DSL-3J08G0M2XB9, which apparently is a 5V SKM36 encoder, is sometimes used on MPL-A1XX motors. It is not clear whether this is an AB part number or Stegmann. But,
the encoder seems to test fine using the SKM36 selection.

The following list includes conventional incremental encoders with commutation signals and/or Hall effect
pickups.

 

Identification

F, H, N, S, and Y Series –

The part number breakdown for these motors is as follows:

 

B & P Series –

Typical B and P series part numbers would be B14H1060 and P21M0304G. In the examples we have seen, the B series motors are 4 poles P series motors are 6 poles.

 

MPS, MPL, MPF, 1326AB and 8720-

The part number breakdown for the P series motors is as follows:

Generally it seems that the MPL-A type motors use 4.5-12.0V Stegmann encoders, and the MPL-B type are 7.0-12.0V. Reading the feedback designator tells you what kind of feedback is in use.

 

1326AB –

Part numbers for the 1326AB are as follows:

 

8720 Spindle Motor –

The part number breakdown for the spindle motors is as follows:

 

Connection

Connection requires using the correct cable as shown in the chart in the Type Supported section. Also the Athena ‘Feedback Selection’ frame has a cable dropdown menu from which you can select the cable that you need. After making the cable selection, that selection will appear on the Data Display report which is helpful in documenting the cable used.

The TI-5069 and TI-5094 generic cables connect directly to the 8 pin or 9 pin encoder connector, so they should work with all Hiperface encoders (depending on the exact encoder connector used). Download cable sheets from the Customer Page at http://www.mitchell-electronics.com for cable pinouts and wiring details.

In most cases, test cables that connect directly to the motor feedback connector are available (the TI-5064 for instance). These cables offer the advantage of testing through the cable harness on the motor (which could be where a problem exists). In the case of the 1326AB motors, when you remove the encoder cover to connect directly to the encoder, the encoder body is free to move. After you align the encoder, it could move when you remove the test cable and install the cover. With the TI-5064 cable, you can check the alignment after the encoder cover has been installed.

If properly cabled, the Stegmann Hiperface encoders can be used with the TI-5104 Adapter Module so that it is easier provide the correct power supply voltage and to check the incremental portion with the same connection. See the section on cables for more information.

 

Data Display

Commutation

The electrical angle is best for checking and setting commutation for serial encoders. For a particular lockup polarity, the rotor will lock up in as many different positions as there are pole pairs but the electrical angle indications will be the same at each lockup position. The mechanical angle will be different at each lockup position (except for 2 pole motors where there is only one lockup position), so mechanical angle is not as convenient to use for feedback alignment. For some motors with incremental encoders or Hall effect signals, it is necessary to use the commutation signals for alignment. See section 3.2 for a more detailed description of commutation alignment procedures.

The number of poles must be entered correctly for the electrical angle to be displayed correctly. The electrical angle and mechanical angle are derived from the position count. The position count is absolute immediately on power up for Stegmann Hiperface encoders.

The method of alignment for Allen Bradley motors will vary with motor the motor model. The various models are discussed below.

 

F, H, N, S, and Y Series –

A few of these motors use Stegmann Hiperface encoders. Refer to the section below on MPL motors when a Hiperface encoder is used. Most of these motors use Renco encoders. On the older motors, there are Hall effect pickups to provide the commutation signals. Newer motors use a commutation track on the encoder for commutation signals. The alignment is the same in either case.

The R, S, and T armature leads are U, V, and W respectively. The TI-5019Q and TI-5045Q cables will connect the corresponding commutation signals to TI-5000JX H1, H2, and H3 respectively. This is important because the A, B, and designations in the AB literature do not correspond with the R, S, and T armature voltages (A=H3, B=H1, C=H2).

The first two lockups indicate the proper alignment for the commutation signals. If the encoder has been aligned and indexed, the electrical angle shown should also appear.

The third lockup will give you a zero electrical angle if the encoder has been aligned properly and indexed.

 

B & P Series –

The B & P series motors use Ono Sokki encoders. These encoders provide the commutation signals as well as the A, B, and Z counting signals. The TI-5091 cable will connect the corresponding commutation signals to TI-5000JX H1, H2, and H3 respectively.

The first two lockups indicate the proper alignment for the commutation signals. If the encoder has been aligned and indexed, the electrical angle shown should also appear.

The third lockup will give you a zero electrical angle if the encoder has been aligned properly and indexed.

 

MPS, MPL, MPF, 1326AB and 8720 –

The table below shows 2 different lockups that can be used to check or set commutation on Allen Bradley motors with Hiperface serial encoders. The two procedures require applying power to only two armature leads at a time. It is easy to go from +U –V to +U –W just by moving the minus lead from V to W. This should cause the motor to jog 60 electrical degrees in the forward direction (CW looking at the shaft for Allen Bradley). Failure to move the correct number of degrees or in the correct direction would be an indication of a significant problem. Setting these angles within ±3 electrical degrees is normally quite sufficient.

Note: This is an example alignment based on encoder data. These motors do not have a standard alignment. The angles you see will be different.

 

Unlike most feedback alignment discussed in this manual, Allen Bradley MPL, MPF and 1326 motors using
Hiperface encoders do not have a common lockup angle, and in general, they will all lock up at different angles. These motors store a commutation offset in the encoder memory. By using the commutation offset, the encoders do not have to be set to a common alignment. In order to correctly check or set the alignment, you have to run the Memory Test on the encoder, and note the +U –V and +U –W lockup angles provided by the memory test.

 

Memory Status

The Read Memory Status button on the Data Display allows the user to check whether memory is currently in use for a particular encoder. Clicking the button when connected to an SRM50 encoder on an Allen Bradley MPL motor would produce the following display:

This tells us that there are 4 memory fields of 32 bytes each defined in this encoder. All 4 fields are write enabled (WE). The access code is set to 0 (could be 0, 1, 2, or 3). The code enable bit (CE) is not set for the 4 defined fields, so the access code does not have to be used. The total bytes number of memory bytes used is 128. The total bytes unused is 0, and this means that all of the available memory is in use. No more data fields could be defined for this memory because it is used up.

This data formatting is done by the motor manufacturer and is of little concern to the TI-5000JX user. However, it is useful to look at it to verify that the memory looks normal. For instance if you see that no fields have been defined for an encoder on an Allen Bradley MPL motor, it is very likely that the encoder has been replaced and the correct data has not been programmed into the memory. This would be very important to know because the motor would not run correctly on the Allen Bradley drive. It is also useful to check on unfamiliar motors to determine whether the motor manufacturer is using the memory.

This Memory Status data is automatically included on the Data Display report when a Stegmann Hiperface encoder has been selected.

 

Memory Test

Encoder memory is used on Allen Bradley MPS, MPL, MPF, and 1326 type PM brushless motors and 8720 series spindle motors (this list may not be all inclusive). As explained previously, the Read Memory Status button on the Data Display can be used to determine whether the memory is in use.

When the memory is used, it will normally be programmed with the motor model number and sometimes
motor parameters. The drive can read this memory data on power up and determine what kind of a motor is connected to it. Some manufacturers, such as Allen Bradley and Indramat, are now programming a commutation offset value into the memory. This offset tells the drive the difference in the present feedback alignment from the ideal feedback alignment so that the drive can adjust its timing to compensate for an imperfectly aligned feedback device. This relieves the manufacturer of performing a precise alignment during manufacturing. They simply program in the offset for the drive to read. This means that each motor may be aligned somewhat differently, but the repair shop must still align the feedback the way the drive is expecting it to be. The TI-5000JX memory support will display the proper alignment angles based on this memory data so that the repair technician can properly align the feedback.

Because the way in which the memory is used differs with the various motor manufacturers, software support must be developed for each brand (and sometimes models) of motors. Therefore TI-5000JX memory support must be purchased for each motor type in addition to the basic Stegmann encoder support.

Note: If a Hiperface encoder is replaced on an AB motor, the motor data must be programmed into the replacement encoder in order for the drive to run the motor. Contact Mitchell Electronics, Inc. for information on software support for programming replacement encoders.

 

Allen Bradley Memory Test

Allen Bradley MPL, MPF and 1326 motors use the Hiperface encoder memory to store motor parameters. This data is programmed at the factory and cannot be changed by the drive. This data is read by the drive system on power-up prior to moving the motor. If the drive system cannot read the memory or if it gets incorrect data from it, the motor will not run. It is therefore very important to verify that the memory can be read and appears to be correct. The memory also contains information that allows checking the commutation alignment.

In verifying correct memory data and memory operation, we are looking at two things:

1. Is the data correct and not corrupted?
2. Is it the correct data for this motor?

The first item is done automatically. The data in the encoder is encoded with the ability to check data integrity. The TI-5000JX does this automatically as it reads and displays the various motor parameters. A explanation of possible errors is provided at the end of this section.

The second item amounts to making sure that the encoder that is on the motor is the correct one. Sometimes in trouble-shooting, encoders get swapped in an attempt to isolate a problem, and the encoder on the motor you have could be the wrong one entirely. In general the data from the encoder should match the data from the motor nameplate. In this regard, we are looking for gross errors. Minor differences in the encoder data and nameplate data are normal.

The display shown below is a memory test from an SRM50 encoder. The motor type number and motor parameters are fairly self explanatory. These numbers should match reasonably well with the nameplate data. At the end of the right column is some information that is useful to the repairman. The number of pole pairs is 4, which indicates a, 8 pole motor. This may not be universal, but it appears that the MPL and MPF motors are 8 poles, while the 1326 motors are 4 poles.

The TI-5000JX uses the commutation offset to calculate what the +U –V and +U –W lockup angles should be in electrical degrees for proper feedback alignment, and these angles are reported in the Derived Data
frame.

Comparing the above nameplate data to the encoder data below, we see that the data agrees quite well.

 

The 8729 series spindle motors, using SNS50/60 encoders, will produce a similar result. The spindle motors do not have PM rotor, so there is not alignment. The commutation offset and lockup angles do not appear on the report as they are not applicable to spindle motors.

Each 32 byte block of data in the encoder is encoded with a checksum which allows the ability to check data integrity. The TI-5000JX does this automatically as it reads and displays the various motor parameters. Any incorrect data in one of the data blocks will result in an incorrect checksum calculated for that block. This will be reported with the text “Error” followed by the calculated checksum and then the data from the checksum field. The word “Error” is all you need to see to know that the information is incorrect. If the data is correct, the checksum field will show the text “OK” (as we see in our example). You should assume that if a checksum error occurs, the AB drive will not run the motor.

 

If data errors occur, it could be for any of the following reasons:

1. Faulty encoder.
2. Faulty or no encoder data.
3. Faulty feedback cable from the feedback connector to the encoder in the motor.
4. Incorrect encoder power supply (failure to use the TI-5104 Indramat Adapter Module for 7V encoders).
5. Incorrect or faulty TI-5000JX test cable.
6. Faulty TI-5000JX.

Experience so far indicates that it is somewhat rare for the encoder memory to actually have a problem. If you encounter an encoder data error, check the list above to verify that you are doing everything correctly. 

Especially if you are unfamiliar with testing Allen Bradley motors, you might check with Mitchell Electronics, Inc. if you have an encoder (or several encoders) that do not read the data correctly.

The TI-5000JX software will attempt to pop up a message to help identify possible data problems or incorrect tester selections.

The data from this screen may be saved or printed as a report either in the usual manner with the Save Report to File or Print Report buttons.

The Save Encoder Data File button may be used to save a copy of the data to a disk file as Intel hexcode. You may wish to do this to send to Mitchell Electronics, Inc. in the event that there might be a question about the data. You may also wish to have a copy in case you would need to program it into a replacement encoder in the future.