sat-nms ACU-ODU DC Version User Manual

4.2.1 Angle encoder connection

The angle encoders have to be connected directly to the core module of the sat-nms ACU-ODU, which is called sat-nms ACU-ODM. Inside, the sat-nms ACU-ODM consists of a main board and two or three interface boards with the circuitry for the position sensors. These boards are different for each type of position sensor. Actually interfaces for three types of position encoders are available with the sat-nms ACU:

resolvers
SSI digital position encoders
analog voltage based sensors depending on the interface type you use, different pinouts are used. The following tables show you detailed the pin descriptions: CON18, CON19, CON20 Resolver Interface

Below the pinout of a resolver type interface board is shown. The ACU is available with resolver, SSI or analog position sensor interfaces. You have to select type of interface when you order the ACU.

pin	signal	description	type
1	GND
2	SIN	resolver SIN	IN
3	GND	resolver SIN	IN
4	COS	resolver COS	IN
5	GND	resolver COS	IN
6	REF	drive signal to resolver	OUT
7	GND	drive signal to resolver	OUT
8	GND

The ACU resolver interface is designed for resolvers with an impedance of 100 Ohms or more and transfer factor 0.5. The interface applies 4Veff / 2000Hz to the resolver drive coil. It expects 2Veff at the sine / cosine inputs at the maximum positions.

When connecting a resolver to the ACU, please consider the following:

Use a shielded, twisted pair cable.
Connect the cable shield either to pin 1/8 at the ACU or to the ground at the resolver housing. Never connect the shield at both ends, this will introduce a ground loop and cause a significant degradation of the resolver's accuracy.

CON18, CON19, CON20 SSI Positional Encoder Interface

Below the pinout of a SSI type positional encoder interface board is shown. The ACU is available with resolver, SSI or analog position sensor interfaces. You have to select type of interface when you order the ACU.

The SSI positional encoder may be powered from the ACU internal power supply. +5V and +24V clamps are provided at the connector. To avoid ground loops, the cable shield should be connected either to pin 1 at the ACU or to the ground at the encoder housing, never at both ends.

pin	signal	description	type
1	GND
2	SSI-Data+	SSI data	IN
3	SSI-Data-	SSI data	IN
4	SSI CLK+	SSI clock	OUT
5	SSI CLK-	SSI clock	OUT
6
7	+5V	encoder power supply
8	+24V	encoder power supply

CON18, CON19, CON20 Analog Angle Sensor Interface

Below the pinout of an analog type positional sensor interface board is shown. The ACU is available with resolver, SSI or analog position sensor interfaces. You have to select type of interface when you order the ACU.

pin	signal	description	type
1	AGND	analog ground	OUT
2	INPUT	A/D converter input	IN
3	REF	reference voltage	OUT
4	AGND	analog ground	OUT
5	+15V (opt)	optional DC out	OUT
6	-15V (opt)	optional DC out	OUT
7	+9V (opt)	optional DC out	OUT
8	GND	digital ground	OUT