Additional Resources: Product Page date 09/10/2021 page 1 of 10 SERIES: AMT21 DESCRIPTION: MODULAR ABSOLUTE ENCODER FEATURES high speed protocol for fast low latency position data patented capacitive ASIC technology low power consumption 12 or 14-bit absolute position with multi-turn capability 3.3 V half-duplex RS485 - high speed 2 Mbps or adjustable data rate settable zero position configuration and programming via AMT Viewpoint software compact modular package with locking hub for ease of installation radial and axial cable connections -40 ~ 105C operating temperature ELECTRICAL parameter conditions/description min typ max units power supply VDD 3.8 5 5.5 V 1 start-up time 200 ms current consumption with unloaded output 16 mA Note: 1. Encoder must be stationary during start-up. ABSOLUTE POSITION CHARACTERISTICS parameter conditions/description min typ max units resolution 12 or 14-bit accuracy 0.2 degrees settable via AMT Viewpoint GUI or RS485 (single-turn absolute zero position versions only) multi-turn multi-turn and single-turn versions available 2 turns counter signed binary number 14 bits 12-bit 25 s absolute position update rate 14-bit 100 s Notes: 2. Multi-turn encoders only. MECHANICAL parameter conditions/description min typ max units motor shaft length 9 mm motor shaft tolerance NOM +0/-0.015 mm weight 15.7 g axial play 0.3 mm rotational speed at each 12-bit position resolution 8,000 RPM resolution 14-bit position resolution 4,000 RPM cuidevices.comAdditional Resources: Product Page CUI Devices SERIES: AMT21 DESCRIPTION: MODULAR ABSOLUTE ENCODER date 09/10/2021 page 2 of 10 ENVIRONMENTAL parameter conditions/description min typ max units operating temperature -40 105 C humidity non-condensing 85 % vibration 10~500 Hz, 5 minute sweep, 2 hours on each XYZ 5 G shock 3 pulses, 6 ms, 3 on each XYZ 200 G RoHS yes REACH EC 1907/2006 ( ) RS485 INTERFACE 2 MBPS DATA RATE A,B,C,D OPTIONS parameter conditions/description min typ max units protocol RS485 balanced digital multi-port interface data rate 8 data bits, no parity, 1 stop bit, asynchronous 2 Mbps transceiver Texas Instruments SN65HVD75 turnaround time time before encoder responds with position 3 s driver differential output load resistance = 54 1.5 2 3.3 V voltage magnitude ( ) RS485 INTERFACE ADJUSTABLE DATA RATE E,F,G,H OPTIONS parameter conditions/description min typ max units protocol RS485 balanced digital multi-port interface 8 data bits, no parity, 1 stop bit, asynchronous 3,4 data rate bps 115,200 38,400 19,200 9,600 transceiver Texas Instruments SN65HVD72 time before encoder responds with position 115,200 bps 10.8 s turnaround time 38,400 bps 30 s 19,200 bps 56 s 9,600 bps 110 s driver differential output load resistance = 54 1.5 2 3.3 V voltage magnitude TM Notes: 3. Data rate configured with AMT Viewpoint 4. Default data rate on kits is 115,200 bps. Checksum The AMT21 encoder uses a checksum calculation for detecting transmission errors. The upper two bits of every response from the encoder are check bits. Those values are shown in the examples below as K1 and K0. The check bits are odd parity K1 for the odd bits in the response, and K0 for the even bits in the response. These check bits are not part of the position, but are used to verify its validity. The remaining lower 14 bits are the useful data. Here is an example of how to calculate the checkbits for a 16-bit response, from a 14-bit encoder. Full response: 0x61AB 14-bit position: 0x21AB (8619 decimal) Checkbit Formula Odd: K1 = (H5 H3 H1 L7 L5 L3 L1) Even: K0 = (H4 H2 H0 L6 L4 L2 L0) From the above response 0x61AB: Odd: 0 = (1 0 0 1 1 1 1) = correct Even: 1 = (0 0 1 0 0 0 1) = correct cuidevices.com