In the field of industrial automation and motion control, high-speed and high-precision pulse control has always been a core requirement. The AMP-20xC series multi axis motion control card has become the preferred solution for many equipment manufacturers and system integrators due to its rich interface resources, flexible driver compatibility, and powerful encoder feedback processing capabilities. However, in order to fully utilize the performance of the control card, it is necessary to have a deep understanding of its interface definition, signal characteristics, and wiring specifications. This article is based on the hardware manual of AMP-20xC, systematically sorting out the functional allocation, pin signal description, electrical parameters, and typical application wiring methods of all its connectors, providing engineers with a complete technical reference from installation to debugging.
Overview of Control Card Interfaces
The AMP-20xC adopts a modular interface design, with a 100 pin SCSI main connector (P1) onboard for transmitting all motion control commands and feedback signals; Four 26 pin CMP connectors for connecting mainstream servo/stepper drivers; In addition, it is equipped with a laser control interface (CN1), universal I/O screw terminals (J1, J2), trigger output (J3), brake control (J4), main power and emergency stop (J5), isolated digital output (J6), and 37 pin D-SUB expansion I/O (P2). The four 9-pin IOIF screw terminals provide 16 isolated digital inputs and 16 isolated digital outputs. Such a rich interface layout enables AMP-20xC to manage up to 4 axes (standard version) or 8 axes (extended version) simultaneously, covering all necessary signals such as pulse direction control, CW/CCW mode, encoder ABZ feedback, limit/origin switch, servo alarm and enable, etc.
Main connector P1-100 pin SCSI interface detailed explanation
P1 is the most core signal channel between the control card and the external servo/stepper driver. Its 100 pins are grouped according to the axis number, with approximately 20 pins allocated to each axis, supporting a four axis standard configuration. The pin allocation table clearly defines the differential pulse output (OUT+/- and DIR+/-), differential encoder feedback (EA+/-, EB+/-, EZ+/-), servo alarm input (ALM), origin limit input (ORG), positive and negative limit (PEL/MEL), zero speed detection (ZSP), servo enable output (SVON), and universal digital input/output (EDI/EDO) for each axis.
1. Pulse output and directional signal
Each axis is equipped with a pair of differential pulse outputs (OUT+/-) and a pair of differential directional outputs (DIR+/-), for example, axis 1 corresponds to pins 13/14 (OUT1) and 15/16 (DIR1), axis 2 corresponds to pins 17/18 and 19/20, and so on. These differential signals use line driven outputs (such as 26LS31), with a default output type of pulse+direction, but can also be configured through software as CW/CCW forward/reverse pulse pairs. The manual specifically states that it is recommended to connect the OUT -/DIR - terminal to the signal ground terminal of the driver to ensure common mode noise suppression. At the same time, it should be noted that the current flowing through the differential output terminal should not exceed 20mA, otherwise it may damage the driver chip. In practical wiring, it is recommended to use twisted pair shielded wires and ground the shielding layer at one end to reduce high-frequency interference.
2. Encoder feedback input
Each axis contains three pairs of differential inputs (EA+/-, EB+/-, EZ+/-) for receiving incremental encoder signals from servo motors or grating scales. EA and EB have a phase difference of 90 °, used for position counting and direction discrimination; EZ is the zero position pulse for each revolution, used for precise positioning back to the origin. The manual emphasizes that the common mode voltage range of differential input pairs is allowed to be ± 7V, which means that the driver output must provide a differential voltage swing of at least 0.2V, and the maximum input frequency can reach 5MHz or above (depending on the transmission distance and signal conditioning). For encoders that use open collector output, an external pull-up resistor must be connected to convert the signal into differential form; If the driver has a built-in differential line driver, it can be directly connected. When wiring, it is necessary to ensure that the signal ground (DGND) of the control card and the driver are interconnected, otherwise the common mode voltage may exceed the allowable range.
3. Limit, origin, and servo status signals
Each axis provides three input signals: positive limit (PEL), negative limit (MEL), and origin (ORG), all of which are single ended inputs. The default high level is valid (but can be reversed through software). These signals are usually connected to mechanical travel switches or proximity sensors. In addition, the servo alarm input (ALM) and zero speed signal (ZSP) are used to monitor the status of the drive. When ALM is triggered, the control card can immediately stop pulse output. The servo enable output (SVON) is active at a high level and is used to connect the enable circuit of the servo driver.