In the field of precision motion control, the demand for dual axis synchronous drive is increasing, such as gantry platforms, dual drive laser processing, synchronous scanning systems, etc. The dual axis controllers (DSCDP, DSCDL, DSCDM) in the ETEL DSCxx series integrate two independent servo control channels on a 6U rack board, which can simultaneously drive two single-phase or two-phase linear/rotary motors. Coupled with analog sine and cosine (including EnDat 2.1 absolute value) or TTL encoders, they achieve sub micron level positioning. However, the debugging complexity of dual axis systems is much higher than that of single axis systems - from dual axis DIP switch address allocation, independent encoder wiring isolation, dual channel initialization and zeroing, to separate tuning of two axis regulators, any parameter mismatch in any link can lead to system errors or even motor runaway. This article is based on the core content of the DSC series operation and software manual (version F), combined with the unique structure of the dual axis controller, and systematically outlines the key steps and typical troubleshooting strategies for on-site debugging.
Dual axis model identification and hardware differences
The DSC series dual axis controller includes three main models, with differences in hardware characteristics and applicable scenarios:
1.1 DSCDP
Dual axis servo controller, supporting three-phase motors (star connection), PWM frequency 18kHz.
Peak current per axis is 11A (2 seconds), suitable for medium power dual axis applications.
Supports digital Hall sensors (K90=3/4/5), without built-in analog input (different from DSCDL).
1.2 DSCDL
Dual axis linear motor dedicated controller, supporting single-phase/two-phase motors.
The current loop sampling time is 13.89 μ s (72kHz), which is the fastest among the three and suitable for low inductance linear motors.
Each axis is equipped with one analog input (AIN, ± 10V, 16 bit ADC), supporting EnDat 2.1 absolute encoder (K79=4).
Support small displacement initialization (K90=6), suitable for vertical axis or high friction systems.
1.3 DSCDM
Low cost dual axis controller, with multiplexed pins for digital I/O and analog I/O (direction selection required through K171).
Without DIN2, returning to zero requires selecting DIN1 or DIN9 as the Home switch input through K58 (bit2/bit3).
Only supports ± 36VDC power supply (SELV), with a power-off discharge time of only 2 minutes (different from other models' 10 minutes).
On site selection prompt: If it is a linear motor dual axis application and requires analog speed/torque commands, DSCDL should be prioritized; If it is cost sensitive and only requires digital I/O control, DSCDM is more economical.
Dual axis axis number setting and TEB communication
2.1 DIP switch axis number allocation rules
The axis number of the dual axis controller is set through a 4-digit DIP switch, and the rule is different from that of a single axis:
Axis number=DIP switch binary value x 2
The first axis equals the value multiplied by 2, and the second axis automatically increases by 1
Example: DIP switch set to 3 (binary 0011) → first axis=6, second axis=7.
Special case: When all switches are turned to "1" (high position), the controller reads the axis number previously saved through the AXI command (if not saved, it defaults to axis 0 and 1).
Common error: If multiple DSCDP/DSCDL/DSCDM share the TEB ring, the axis number must be unique and continuous (such as axis 0/1, 2/3, 4/5...). If "BAD NOTE TEB ERR" (M64=59) appears, it indicates the presence of duplicate axis numbers and requires checking the DIP switch settings of each controller. The manual clearly states that the AXI command must be applied to even axes when using the dual axis controller, and the new axis number must be even.
2.2 TEB Communication and Synchronization (K87)
The TEB synchronization frequency of the dual axis controller is 2kHz (STI=500 μ s), which is different from the 6kHz of DSC2P/DSC2V. In multi axis interpolation mode, it is necessary to set:
The optimal K87 value for DSCDP/DSCDL/DSCDM is 257 (bit0=1 synchronized at 2kHz, bit8=1 delayed by 1 FTI=55.56 μ s).
If K87=0 (asynchronous), TEB communication can still work, but the accuracy of multi axis interpolation decreases.
Dual encoder independent wiring (JC5/JC6)
DSCDP/DSCDL/DSCDM provide independent encoder interfaces for each axis (JC5 corresponds to motor 1, JC6 corresponds to motor 2), both using 15 pin high-density D-Sub female sockets.
3.1 Encoder type and K79 parameters
Dual axis controller supports:
K79=0: Simulate sine cosine (1Vpp) encoder, requiring K70~K73 (offset/amplitude correction) to be set.
K79=4: EnDat 2.1 absolute encoder, attention should be paid to clock frequency of 500kHz and cable length ≤ 150m (distributed capacitance of 90pF/m).
K79=1: TTL encoder (RS422), input frequency limit of 400kHz (limited by analog front-end).
Special precautions for dual axis:
The power supply (+5V) of the two encoders is protected by independent 1A fuses (F2). If the power supply of one axis encoder is blown, only that axis will report "ENCODER FUSE KO" (M64=35).