Typical supply current: 250mA (with Vs = 12V) including handpaddle and no accessory loads.
Fusing
Main fuses: 2A fast-blow. One for each axis (RA/Az and Dec/Alt).
Limits and Drive ports +5VDC: resettable fuse for each axis with a minimum hold current value of 240mA (high temp). Do not operate above 240mA.
Axial and Motor encoder ports +5VDC: resettable fuse with a minimum hold current value of 500mA (high temp). Do not operate above 500mA.
Drive port
Step, Dir and En signals
Output driver:
Push/pull driven from 5VDC or Gnd.
100 ohm output impedance.
25mA max source/sink current.
Issues up to 250,000 steps per second.
Step/Dir timing:
Step pulse: active low signal. Step line is quiescent high.
Min step pulse width: 1.8us at 250,000 steps per second.
Dir timing w.r.t. to Step
Setup time to step edge: 1us min
Hold time from step edge: 1us min
Digital inputs/outputs
Inputs
Includes: Autoguider, Hard Limit (HL), Axial Limits (LiN & LiP), Home Index (HI), Gear Index (GI) and Gear Index Gate (GIG)
Internal 2.2kOhm pull-up to +5V
Max input low voltage: 0.66V
Min input high voltage: 2.64V
Min pulse width on Home and Gear Index: 1us
Outputs
Includes: general purpose assignable outputs DOY and DOX.
Push/pull driven from 5VDC or Gnd.
100 ohm output impedance.
25mA max source/sink current.
Isolated inputs/outputs
O+/O-: assignable output port
Output driver:
Open collector (pull-down only) from O+ to O-.
Output current: 25mA max.
Rload: 200 Ohm min pull-down from 5VDC.
Output low voltage (voltage on O+ - voltage on O-)
200 Ohm Rload: output voltage typical of 0.7V.
≥1k Ohm Rload: output voltage typical of 0.1V or lower.
I+/I-: assignable input port
Input specifications between I+ and I-:
Vmin: -24V... minimum allowed voltage
Vop: 3.0V min... minimum voltage to signal asserted input
Vmax: 24V... maximum allowed voltage
Input impedance: 2.2kOhm
Analog inputs
An0 and An1 analog input specifications:
Vmin: 0V
Vmax: 3.3V
Autoguider input
Connects to any “relay activated” autoguider.
Correction is applied at a settable velocity.
Provides industry standard SBIG pinout into an RJ12 connector:
Control switches
Drive disable toggle switches for each axis.
Hard Limit over-ride push buttons for each axis.
Balance toggle switches for direct drive motor systems (per-axis drive and brake disable).
Indicators
For each motor driver: status (Red): flashing slowly for normal operation.
For CPU: status (Red): long flash when not communicating with client, short flash when communicating.
Per-axis Disable (Yellow): lit if the motor drive is disabled.
Per-axis Hard Limit (Red): lit in Hard Limit condition (can override with push button).
Motor and Axial encoder interfaces
Supports standard quadrature output encoders.
Optional absolute encoder support (SSI, BiSS, EnDat) on the Axial encoder with the HRAO (High Resolution Absolute encoder Option) firmware upgrade.
Up to 4MHz count rate (250ns min quadrature pulse width). This is 90deg of the incoming channel A and B signals. Min channel A and B period is 1us or 1MHz.
Accuracy and resolution
Maximum motor steps per axial revolution: 999,999,998.
Maximum encoder counts per axial revolution: 999,999,998.
Internal calculation accuracy is to one motor step or one encoder count, whichever is larger.
Max cable lengths
TCS: 40’ (12.2m) as max sum of all cables on all TCS ports.
