ACU6

Type 6 of ANSARI's Controlling Unit with Focus on PLC

» Posted on 11. Jan 2013

click to download PDF ACU6 ~ Technical Reference Manual  

 

ACU6 – Controlling Unit

 

 ACU6_3D_assembly

 

DESCRIPTION

ANSARI’s Controlling Unit – Type 6 (ACU6) is designed to build a sensor and/or actor module in the field to cover many customer requirements in a very small form factor. One of the major advantages of this module is the ability to communicate over the power line with speeds up to 57600 baud.

If ACU6 is used as a sensor module it is capable of storing sensor data locally using an onboard serial Flash up to 64MByte of capacity. Together with each record, the ACU6 can also store a time stamp and the temperature of the sensor at the recording time.

The form factor of ACU6 is kept so small, that it can be integrated into a very small housing. The PCB is optimized to be fitted into M12 screw housing usual in the industry.

ACU6_PLC_block_diagramThe communication over power line reduces harness and connector size, increases reliability, saves node costs and increases the network throughput.

The transceiver operates as an AC/DC power line transceiver that replaces the RS232 transceivers thus eliminating the extra data wires. It contains a host UART interface, modem and line driver and receivers. A virtual network is created over the power line, which consists of a Master and Salves.

Unlimited number of ACU6 modules can be networked together over 2 wires of power line to build complex virtual groupings of sensors and actors.

Each module may operate as a slave in a multiplex network. Multiple networks may operate concurrently over the same power line by using different carrier frequencies. Supported channel frequencies are: 4.5 MHz, 5.5 MHz, 6 MHz and 6.5 MHz, but only two of the frequencies are supported in a configuration at a time, which is definable at assembly time. Data transfer rates are software selectable between 9.6 kbps and 57.6 kbps. Each module is able to operate without a need of a host.

Digital processing and interfacing of the module is based on a 16-bit RISC processor with 16 MIPS, 128 kByte Flash and 10 kByte SRAM. The ADC module is a 200 ksps fast 12-bit SAR analog-to-digital converter with reference generator for sensor biasing if needed.

Powerful signal conditioning at input stage allows interfacing of various types of sensors to this module. The analog input is a current-feedback instrumentation amplifier that consists of two auto-zeroed input stages. These two input stages are operated in a ping-pong fashion: as one stage is auto-zeroed the other stage provides the path between the input pins and the output. The auto-zeroing decreases offset, offset drift, and 1/f noise while the ping-pong architecture provides a continuous path between the input and the output.

ACU6 can support many different digital type of I/O signals to cover various small signal controlling and driving requirements in an actor. It can also build a gateway between power line data and I²C, SPI or UART interfaces.

 

BLOCKDIAGRAM

 

ACU6_block_diagram 

 

FEATURES

  General
   
  • 16-bit mixed signal RISC microcontroller with 16 MIPS
  • 128kByte code Flash, 10Kbyte SRAM and additional 4MByte external serial Flash
  • 12-bit 200ksps Analog-to-Digital converter with Reference voltage and auto scan
  • Basic timers with real-time clock feature and time stamp for logging purposes
  • SPI controlled programmable gain amplifier with input multiplexer
  • Local long term logging capability for 500.000 records with time & temperature stamps
  Power Line Data Interface
   
  • Noise robust UART over power line transceiver
  • Four selectable carrier frequencies
  • Selectable bit rate between 9.6 kbps and 57.6 kbps
  • Operates as master or slave in a multiplex network
  • Multiple networks may operate over the same power line
  • Communicates over wide range of AC/DC voltage lines
  Sensor Input Interface
   
  • Low Noise: 28nV/Hz
  • Offset: 10µV (max)
  • Zerø Drift: 50nV/°C
  • Input Offset Current: 2nA max
  • Gain Error: 0.15% max
  • Gains: 10, 20, 50, 100, 200, 500, 1000
  • Operating temperature range -40°C to 125°C
  • GBW: 8kHz to 8MHz
  • Input channel MUX
  • Min CMRR 110 dB
  • Max non-linearity 100 ppm
  • Max gain drift 16 ppm/°C
  • Input fault detection

 

APPLICATIONS

There are 4 major focuses for ACU6:

Sensor module

able to handle two sensing channels for any combination of sensors like: Light-, IR-, Gas-, Motion-, Temperature-, Humidity-, Smoke-, Magnetic-  or other sensors/detectors applications.

Actor module

able to handle driving signals for many actions in the environment like turning a device on or off, driving a DC- or Step-motor, driving magnetics for mechanical motions, etc.

Gateway module

Being a gateway between different interfaces like SPI, I²C, UART and the power line communication.

Local long term logging capability

The ACU6 is able to log sensor data together with a time and temperature stamp per record. More than 5 million records can be stored in the ACU6. If each minute one record is stored, the ACU6 can store the data of several years locally!

Of course mixing of mentioned capabilities listed above, is also supported as long as I/Os are given. 

In general, the major applications supported are those, which get attractive when communication over power line is desired. Especially virtually grouping of modules and networked modules, unlimited in the number, over same power line wires are well supported applications by ACU6 on system interfacing side. On the local interfacing side many known applications can be covered by the analog and digital interfaces realized in the electronic.

ACU6_3D_assembly_with_FeMale_SMA_in_M12

The figure above shows the ACU6 module implemented into M12 housing. The front of M12 tube can
be assembled with a desired sensor or actor as needed. Using a SMA type connector to connect the power line to the module is an option to secure more the modulated data over the power line against a noisy environment. The room between the SMA connector body and the M12 tube itself allows the LED lights on the board to illuminate the status of the module to outside world if a transparent adhesive material is used to fix the module inside the tube.

If desired a shielded or non-shielded cable can be directly soldered to the module and be fixed together into the housing to reduce material cost.

The ACU6 is also as an add-on module available to be connected into other equipment over header connectors as shown in the figure below. The pinning of the connectors is compiled in a way, so that many applications can be realized using only one or two of shown connectors in the figure to operate fully in a desired application. The connectors may be selected as male or female types.

ACU6_3D_assembly_with_2x5_FeMaleCon_90°

The switching mode power supply on the board (SMPS) generates 5V out of the input voltage and is capable to drive up to 300mA current. The board itself needs only about 60mA of this current internally. The carrier board can use this 5V for its needs as long as the current consumed doesn’t exceed 220mA.

 

DIMENSIONS

All dimensions are in millimeters.

ACU6_PCB_dimensions

Printed Circuit Board (PCB) design

The PCB is routed on 6 layers with chem. gold surface and 18µm thick Cu for each layer.
The PCB is built using FR4 material. The PCB thickness is about 1mm. 
Minimum Cu-Cu gap size is 0.1mm, smallest track size on the layers is 0.1mm and minimum drill size is also 0.1mm. A number of 188 drills are used on the board and all via’s are plugged.

ACU6_CAD_with_COT2

  

Electrical Interface

 ACU6_Interface

 

Pin# Pin-Name Type Descriptions
1

TDO
Int3
PM7

GPIO

In JTAG mode: data out pin
In normal mode: either as an interrupt input pin or as a normal
GPIO pin or in special port mode as a desired peripheral pin

2 Reset Input µController Reset pin
3

TDI
Int2
PM6

GPIO

In JTAG mode: data input pin
In normal mode: either as an interrupt input pin or as a normal
GPIO pin or in special port mode as a desired peripheral pin

4 SenAct-IO3   Analog  
GPIO

µController analog input pin for ADC/Comparator or
general purpose I/O pin

TMS
Int1
PM3

GPIO

In JTAG mode: TMS pin
In normal mode: either as an interrupt input pin or as a normal
GPIO pin or in special port mode as a desired peripheral pin

SenAct-SGV Power Sensor Ground Voltage(SGV), configurable in 8mV steps

TCK
Int0

GPIO

In JTAG mode: Clock pin
In normal mode: either as an interrupt input pin or
as a normal GPIO pin 

SenAct-IO2 Analog
GPIO

µController analog input pin for ADC/Comparator or
a general purpose I/O pin or
in special port mode as a desired peripheral pin or
negative analog sensor input signal
(Same as pin#13)

GND Power Ground pin
10    SenAct-PWR    Power

Power Supply for connected sensor or actor element or
main power supply switched over Q2 and body diode of Q2
(Same as pin #11)

11  SenAct-PWR Power

Power Supply for connected sensor or actor element or
main power supply switched over Q2 and body diode of Q2
(Same as pin #10)

12  SenAct-IO1 Analog
GPIO

µController analog input pin for ADC/Comparator or
a general purpose I/O pin or
in special port mode as a desired peripheral pin or
negative analog sensor input signal
(Same as pin#13)

13  SenAct-IO2 Analog
GPIO

µController analog input pin for ADC/Comparator or
a general purpose I/O pin or
in special port mode as a desired peripheral pin or
negative analog sensor input signal
(Same as pin#8)

14  GND Power Ground pin
15  Vin- Power Ground pin
16  Vin+ Power Main Input Power Supply
17  +5Vout Power +5V regulated output supply (for external loads up to 200mA max.) 

 

 

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