| Parameter | Value |
| Max. Shaft Axial Play |
±0.010 in. |
| Max. Shaft Eccentricity Plus Radial Play (1) |
0.010 in. |
| Max. Acceleration |
100000 rad/sec² |
| Weight |
2.5 oz. |
| Moment of Inertia |
0.0001 oz-in-s² |
| Max. Shaft Length |
0.60 to .80 in. from mounting surface |
(1) Any non-zero shaft radial play will result in angular errors beyond the specified limits.
- Specifications apply over entire operating temperature range.
- Typical values are specified at Vcc = 12V and 25C.
| Parameter | Min. | Typ. | Max. | Units |
| Supply Voltage |
5.5 |
12 |
16 |
V |
Supply Current
Active
Sleep |
|
14 |
18.5
1.5 |
mA |
| Analog Output Impedance |
950 |
1000 |
1050 |
Ohms |
| Zero Scale Analog Voltage |
0 |
0.0005 |
0.003 |
V |
| Full Scale Analog Voltage |
4.079 |
4.095 |
4.111 |
V |
| Output Noise (Analog version) |
|
10 |
|
mVrms |
| Differential Nonlinearity |
-1.0 |
|
1.0 |
LSB |
| Absolute Accuracy (SEI interface version) |
|
0.18 |
0.25 |
Degrees |
Angle tracking speed
Single-turn mode
Multi-turn mode |
|
|
3600
1800 |
rpm |
| Position Update Rate (1) |
|
|
4 |
msec. |
(1) The internal microcontroller takes a snapshot of the disk every 4 msec. and stores the position in memory. It responds immediately to a "report position request" by sending this value which is always the most current position.
| Parameter | Default value
| Volatile? |
SEI address
|
2 |
Non-volatile |
| Resolution |
3600 |
Non-volatile |
| Origin offset |
0 |
Non-volatile |
| Baud rate |
9600 |
Volatile |
| Mode |
0 |
(1) |
(1) Mode is always restored from non-volatile EEPROM on power-up. However, there are separate SEI commands for setting the RAM copy only, or both the RAM copy and the non-volatile EEPROM copy.
The analog version of the A2K has a 12-bit DAC on the output which feeds to 2 lines that are otherwise used for the BUSY handshaking pair. This DAC has a full range of 0 to 4.095 volts which is 1 millivolt per bit. The value which the internal microcontroller sends to that DAC is the same as the digital value that it sends to the host. Since the resolution (which represents the number of codes per revolution) is field programmable, the range of the DAC will also follow that setup. The default resolution is 3600 codes per revolution which yields 1 count per tenth of a degree. This makes the DAC output equal to 1 millivolt per tenth of a degree or 0 to 3.599 volts. When the DAC needs to have the full range to 4.095 volts, the single turn resolution should be set to 4096. This is easily done with the available software which runs on a PC. Cable CA-MD6A-SS-MD6-6FT and either the SEI-USB or the AD2B adapter are needed to interface the A2K analog version to a USB port or RS-232 serial COM port.
Please Note: The BUSY handshaking lines are replaced by the analog output option. This means that only one device will be able to be connected to the SEI bus when using the analog output option.
H-option
The H-option adds a hole in the housing allowing the shaft to pass through the encoder.
M-option
With the M-option adapter plate the 4 holes in the plate will mount to a 3" diameter bolt circle.
Each A2K is shipped with all encoder components, centering tool, hex wrench, two #4-40 x 3/16" base mounting screws and two #4-40 x 1" cover screws. The following part numbers are provided if spares are needed.
1. Centering Tool
Part #: CTOOL - (Shaft Diameter)
Description: This reusable tool provides a simple method for accurately centering the A2K base onto the shaft.
Instructions: When mounting encoder base, slide centering tool down shaft until it slips into centering hole of encoder base. Tighten mounting screws, then remove centering tool.
2. Hex Tool
Part #: HEXD-050
Description: Hex driver, 0.050" flat-to-flat for #3-48 or #4-48 set screws.
Part #: HEXW-050
Description: Hex wrench, .050" flat-to-flat for #3-48 or #4-48 set screws.
3. Spacer Tool
Part #: SPACER-13
1. Base Mounting
Secure base by inserting screws through holes on the 1.812" bolt circle. Holes in base are designed for #4 screws. Use the centering tool to align base with existing shaft.
2. Spacer Installation
Place spacer tool on circuit board as shown. Position hub/disk assembly above shaft as shown. Slip over shaft and press down until hub and spacer tool bottom out against base.
3. Tightening Set Screw
Press the hub disk against the spacer tool and tighten the set screw with the hex wrench provided. The set screw should be snug, but do not overtighten. Remove the spacer tool.
4. Cover Installation
Important: Cover must be oriented as shown. Because cover plugs into the base, use caution during installation. The posts on the base are two different lengths. Match the cover to mate with the proper post. Connector pins can be damaged if not lined up properly. Secure with two 4-40 X 1" pan head screws provided.
