4. Universal digital I/O
Each axis also includes two sets of universal digital inputs and outputs (EDI1/EDO1 to EDI4/EDO4), distributed on pins 47-50 and 97-100 of P1. Are these I/O isolated or TTL type? According to the subsequent description, EDO is an isolated digital output, but the specific electrical characteristics need to be seen in the descriptions of J6 and IOIF. In fact, the EDO/EDI on P1 belongs to the isolated type, and its common terminals (DICOM, DOCOM) require an external 24V power supply.

Detailed explanation of auxiliary connector functions
1. CMP1~CMP4- Driver specific connection port
These four 26 pin connectors are specifically designed for direct connection to mainstream servo drives such as Mitsubishi J3/J4, Yaskawa Sigma II/III/V, Panasonic MINAS A4/A5, Delta A2, etc. Its internal signal is completely consistent with the corresponding axis of P1, but it provides a more compact wiring solution. If non-standard drivers are used, users can choose single ended open type universal cables and define their own pin functions.
2. J1/J2- Motion I/O screw terminals
Two 10 pin screw terminal blocks, providing EL+(positive limit), EL - (negative limit), ORG (origin), and universal I/O respectively. Actually, J1 and J2 correspond to axis groups 1/2 and 3/4, respectively? From the pin numbers, J1 includes DICOM, EDI3/4, etc. Please refer to the table in the PDF for details. Please note that DICOM must be connected to a+24V external power source, and DOCOM must be connected to an external power ground (IGND). These signals are all optically isolated inputs with strong anti-interference ability.
3. J3- Trigger Output
J3 provides a differential output pair of two trigger signals (TRG1, TRG2), used to generate high-speed pulses when the encoder count value reaches the preset position, commonly used for camera shutter triggering or laser light output control. Its electrical characteristics are similar to pulse output.
4. J4- Brake Control
J4 consists of 4 sets of brake signals (one set per axis), used to control the mechanical brake of the servo motor. Each group contains positive (+) and negative (-) outputs, which can directly drive a 24V electromagnetic brake, but attention should be paid to the current capacity.
5. J5- Main power supply and emergency stop
J5 is the power supply and emergency stop input interface of the control card. Pin 1 is I24V (external+24V power input), Pin 2 is IGND (power ground), Pin 3 is DICOM (digital input common terminal, needs to be connected to+24V), Pin 4 is DOCOM (digital output common terminal, needs to be connected to IGND), and Pin 5 is EMG (emergency stop input). The emergency stop signal uses B-type normally closed contacts. When the EMG is effective (i.e. the contact is disconnected), the control card immediately prohibits all pulse outputs until the fault is resolved. The contact capacity of this switch should be at least+24V/6mA.
6. J6- Isolated Digital Output
J6 provides 4 isolated digital outputs (EDO1~EDO4), designed with MOSFET circuit, with a maximum current of 250mA per channel, which can directly drive small solenoid valves, relays or indicator lights. The output common terminal is DOCOM and must be connected to IGND. Note that these outputs are of the open drain type, and the load needs to be connected to an external pull-up resistor to a 24V power supply.
7. IOIF1~IOIF4- Isolation I/O Expansion
These four 9-pin screw terminals provide a total of 16 isolated digital inputs and 16 isolated digital outputs (each IOIF contains 4 DI and 4 DO), with pin definitions similar to J1/J2 but assigned different axis numbers. These I/O are suitable for long-distance signal transmission, improving the system's anti-interference ability.
8. P2-37 pin D-SUB TTL I/O
P2 is a 16 channel input and 16 channel output for high-speed TTL level, with pins including TDI1~TDI16 (input) and TDO1~TDO16 (output), as well as a+5V power supply and digital ground. These signals are non isolated and suitable for connecting PLC or high-speed counting modules, but attention should be paid to level matching (5V TTL). The manual also mentions that the DO on P2 supports high current (up to 250mA), but requires an external DIO24V power supply (i.e. 24V pull-up), otherwise it cannot provide sufficient driving capability.
Key wiring specifications and precautions
1. Connect the power supply to the common terminal
All isolated inputs (DICOM) must be connected to the positive pole of an external+24V power supply, and all isolated outputs (DOCOM) must be connected to the negative pole of the same power supply (IGND). If different power sources are mixed, it may cause the optocoupler to fail to conduct correctly or be damaged. J5 has provided I24V and IGND terminals, it is recommended to take power from here.
2. Emergency stop circuit design
The EMG signal is a normally closed input, which means that the contact is closed during normal operation and triggers an emergency stop when it is urgently disconnected. If normally open contacts are used, they can be reversed through software configuration logic. Be sure to use an emergency stop switch with sufficient rated current and connect it in series between EMG and DICOM (there is actually an internal pull-up, but the manual does not provide detailed instructions, it is recommended to refer to the schematic diagram). The usual practice is to connect one end of the emergency stop switch to+24V and the other end to the EMG pin.