Product Description #

The RevPi AIO is an expansion module of the Revolution Pi product family with 4 analog inputs, 2 analog outputs and 2 RTD channels.

Components #

revpi-aio-aufbau
Position Component Application

1

3 × status LED

LEDs

2

6 × analog input
2 × analog output

Pinout
Analog Inputs
Analog Outputs

3

X4 connector

Connecting the Power Supply

4

Locking clamps

Mounting the Device on a DIN Rail

5

Ventilation Slots

Mounting the Device on a DIN Rail

6

2 × PiBridge

Connecting Expansion Modules

Pinout #

The RevPi AIO has

  • 2 analog outputs for current or voltage

  • 4 analog inputs for current and voltage

  • 2 RTD channels for resistance temperature sensors (Pt100/1000)

The pins on the connector are assigned as follows:

revpi-aio-pinout

For the configuration, see Configuring RevPi AIO in the PiCtory Value Editor .

LEDs #

The LEDs indicate different device statuses.

Power #

Signal Function

Green

The connection to the RevPi base module is established.

Flashes red

The connection to the RevPi base module is being established (initialization phase).

Red

The connection to the RevPi base module is interrupted.

OUT #

Signal Function

Off

The connection to the RevPi base module is not yet established (initialization phase).

Green

Outputs are ready for operation.

Flashes red

Range error. The values of the RevPi base module are too high or too low.

Red

Error at the outputs.

IN #

Signal Function

Off

The connection to the RevPi base module is not yet established (initialization phase).

Green

Inputs are ready for operation.

Flashes red

Range error. The voltage or current applied to one or more outputs is too high.

Compatible Base Modules #

  • RevPi Connect 5

  • RevPi Connect 4

  • RevPi Connect SE (left side only)

  • RevPi Connect+ (left side only)

  • RevPi Connect S (left side only)

  • RevPi Core (all variants)

See Rules for the Arrangement of Devices.

Scope of Delivery #

The scope of delivery includes

  • RevPi expansion module

  • PiBridge plug connector

  • X4 connector

  • 2 × 14-pin I/O module

  • 2 × blind plug for PiBridge

  • Supplement

Mounting and Connecting #

The RevPi was developed for use in a control cabinet. Observe the specifications for the Intended Use and all Safety Instructions.

Warning
Danger to life due to electrical shock

There is a risk of fatal electrical shock when working on devices in the switch cabinet with 230 V mains voltage.

▷ Operations in the switch cabinet may only be carried out by qualified electricians.

▷ Before carrying out any operations in the switch cabinet, switch off the power supply properly.

Carry out the mounting and connection in the following order:

  1. Mount the RevPi base module and all expansion modules on a DIN rail.

  2. Connect the expansion module via the PiBridge plug connector.

  3. Connect all other devices such as sensors and actuators.

  4. As the last step connect the power supply.

Configuration #

The RevPi expansion modules are configured via the System Configuration with PiCtory.

Configuring RevPi AIO in PiCtory #

The RevPi AIO has:

  • 2 analog outputs for current or voltage

  • 4 analog inputs for current and voltage

  • 2 RTD channels for resistance temperature sensors (Pt100/1000)

These can be configured in PiCtory’s Value Editor.

Mind the Pinout.

▷ Start PiCtory.

▷ Insert the RevPi AIO from the Device Catalog > I/O Devices into the correct slot in the Revolution Pi system on the Configuration Board.

▷ If necessary, adjust the basic configuration of the RevPi AIO under Device Data.

▷ Configure the settings in the Value Editor (see below).

▷ Save the configuration via File > Save as Start-Config. .

▷ Restart the driver via Tools > Reset Driver .

Analog Inputs #

The inputs can be set as either voltage or current inputs, e.g. for motion or level sensors with analog outputs (typically 4 …​ 24 mA or 0 …​ 10 V).

IN 1 — Input 1 #

PIN Usage

24

- negative input for current or voltage measurement channel 1

26

*a wire bridge must be installed for current measurements from here to pin 28

28

+ positive input for current or voltage measurement channel 1

IN 2 — Input 2 #

Pin Usage

23

- negative input for current or voltage measurement channel 2

25

*a wire bridge must be installed for current measurements from here to pin 27

27

+ positive input for current or voltage measurement channel 2

IN 3 — Input 3 #

Pin Usage

17

- negative input for current or voltage measurement channel 3

19

*a wire bridge must be installed for current measurements from here to pin 21

21

+ positive input for current or voltage measurement channel 3

IN 4 — Input 4 #

Pin Usage

11

- negative input for current or voltage measurement channel 4

13

*a wire bridge must be installed for current measurements from here to pin 15

15

+ positive input for current or voltage measurement channel 4

Input Values in the PiCtory Value Editor #

Name Value Function

Input1Range …​ Input4Range

Input range for voltage or current measurement according to the connected sensor, typical for industrial sensors are 0 ... 10 V or 4 ... 24 mA.

ADC_DataRate

Frequency for data rate on the analog converter for all 4 inputs.
The rate, at which the values in the process image are updated, is approximately 1/5 of this ADC data rate.

Scaling input 1 ... 4:Input1MultiplierInput1DivisorInput1Offset

Scaling input channels.
Is determined by the three configuration values and calculated from the original value in mV or µA with:
Y = Multiplier/Divisor*X + Offset

Status Messages #

Status messages are output on OutputStatus_1 …​ 2 in the event of an error:

Bit Position Status Message

Bit 0 (LSB)

0 = value is higher than the lower limit of the configured range.
1 = value is at least 20 mV or 20 µA lower than the lower limit of the configured range.

Bit 1

0 = value is lower than the upper limit of the configured range.
1 = value is at least 20 mV or 20 µA higher than the upper limit of the configured range.

Analog outputs #

The outputs can either output voltage or current, e.g. for actuators such as frequency converters for speed control.

OUT 1-- Output 1 #

Pin Usage

1

V+ positive output for voltage ranges channel 1

3

I+ positive output for current ranges channel 1

5

- common ground for both output channels 1 and 2 (current and voltage)

7

- common ground for both output channels 1 and 2 (current and voltage)

OUT 2 — Output 2 #

Pin Usage

2

V+ positive output for voltage ranges channel 2

4

I+ positive output for current ranges channel 2

6

- common ground for both output channels 1 and 2 (current and voltage)

8

- common ground for both output channels 1 and 2 (current and voltage)

Output Values in the PiCtory Value Editor #

Name Value Function

Output1Range
Output2Range

Off (output inactive)
0 …​ 5 V
0 …​ 10 V
-5 …​ 5 V
-10 …​ 10 V
0 …​ 5.5 V
0 …​ 11 V
-5.5 …​ 5.5 V
-11 …​ 11 V
4 …​ 20 mA
0 …​ 20 mA
0 …​ 24 mA

Value ranges for current or voltage

Output1EnableSlew
Output2EnableSlew

On
Off

Use / do not use slew rate.

Output1SlewStepSize
Output1SlewStepSize

1
2
4
8
16
32
64
128

Increment of the slew rate.
Increment 1 corresponds smallest bit value (LSB) of the converter.

Output1SlewUpdateFreq
Output1SlewUpdateFreq

258 kHz
200 kHz
154 kHz
131 kHz
116 kHz
70 kHz
38 kHz
26 kHz
20 kHz
16 kHz
10 kHz
8.3 kHz
6.9 kHz
5.5 kHz
4.2 kHz
3.3 kHz

Step cycle frequency for the slew rate

Scaling output 1:
Output1Multiplier
Output1Divisor
Output1
Scaling output 2:
Output2Multiplier
Output2Divisor
Output2Offset

16 bit signed multiplier
16 bit unsigned divisor
16 bit signed offset

Scaling output channels.
Is determined by the three configuration values and calculated from the original value in mV or µA with:
Y = Multiplier/Divisor*X + Offset

Status Messages

Status messages are output on OutputStatus_1 …​ 2 in the event of an error:

Bit Position Status Message

Bit 0 (LSB)

Temperature error output module (continuing overload, short circuit)

Bit 1

Open load error current output (connected circuit too high impedance, e.g. cable interrupted)

Bit 2

Internal CRC error output module (e.g. hardware defect, serious external interference signals)

Bit 3

Range Error: The output value in the process image is outside the configured output range.

Bit 4

Reserved for internal purposes

Bit 5

Supply voltage for the expansion module <10.2 V. Outputs have been switched off.

Bit 6

Supply voltage for the expansion module >28.8 V. The outputs have been switched off.

Bit 7 (MSB)

Timeout when connecting to the RevPi base module (e.g. PiBridge fault, piControl fault). The outputs have been shut down.

If the outputs have been switched off for safety reasons, the outputs are re-available only after a restart of the device or a reset of the PiBridge (e.g. piTest -x).

RTD Channels #

The temperature of connected Pt100 and Pt1000 sensors can be determined via the RTD channels.

Mind the Pinout. Pinout

revpi-aio-rtd-channels

The RevPi AIO uses the 3-wire measuring method for a 2-wire sensor. Therefore, you have to simulate the missing third wire with a wire bridge between pins 10 and 12 and 9 and 18 respectively.

MEM Memory Values in the PiCtory Value Editor #

Specifications for RTD1 apply analogously to RTD2.

Name Value Function

RTD1Type

Pt100
Pt1000

Selecting the sensor type

RTD1Wiring

2-Wire
3-Wire
4-Wire

Selection of measuring method.

RTD1Multiplier
RTD1Divisor
RTD1Offset

16 bit signed multiplier
16 bit unsigned divisor
16 bit signed offset*

Setting scaling for RTD channels. It is determined by means of the three configuration values and calculated in accordance with the following formula from the original value (which exists in 1/10 °C):
Y = Multiplier/Divisor*X + Offset

The scaling can subsequently be used for conversion in other units or for a subsequent calibration of a temperature sensor. A 32-bit integer arithmetic is used for calculations in the RevPi AIO. The results are stored as 16-bit values in the process image. Should the result Y exceed the limits of a 16-bit signed value, the fault will be recognised and the value limited. The output values for scaling factor 1 always have to be stored in the process image in the unit mV or µA respectively.

Example #

In order to manage the temperature in °C without decimal places in the process image, the setting must be the following:

Multiplier = 1, Divisor = 10, Offset = 0

In order to manage the temperature in °F in the process image, the parameters have to be set like this:

Multiplier = 18, Divisor = 100, Offset = 32

For process data in °Kelvin you need these values:

Multiplier = 1, Divisor = 10, Offset = 273

Should an error occur, you receive error messages in the input values of the channels RTD_Status_Ch1 and RTD_Status_Ch2. The values have the following meanings:

Bit Position Function

Bit 0 (LSB)

0 = temperature is higher than -200 °C
1 = temperature is lower than -200 °C (e.g. short circuit in sensor or cable)

Bit 1

0 = temperature is lower than 850 °C
1 = temperature is higher than 850 °C (e.g. a sensor is not connected or cable breakage)

Should the recorded temperature be outside the range, the respective limit will be issued (-200.0 °C or 850.0 °C) and the respective status bit will additionally be set.

In the fields RTDValue_1 and RTDValue_2 you can define symbolic names for the 4 analog input values. With these names you can read out measured values of the connected sensors from the process image with piTest, a self-written program or an application software. The values are given there in 1/10 °C if you leave the scaling at 1.

Status signals in process image #

To evaluate a fault status of the RevPi AIO precisely, your user software has to evaluate the status entry in the process image. Status entries are stored there as input values from the PiControl driver. The position (offset) in the process image can be gleaned for example from the offset export in PiCtory or inquired via the symbolic name of the respective status values also with the piTest command line tool. The meaning of each individual bit belonging to the status bytes can be found in the table below:

Bit Cause LED signal Reaction

Status signals analog outputs

Bit 0 (LSB)

Temperature fault in the output module. The output module has overheated due to being overloaded for a longer period of time (short circuit).

red steady

-

Bit 1

Open load fault from the power output. In the "power output" operating mode, the connected circuit is too highly resistive due to, for example, the circuit being interrupted.

red steady

-

Bit 2

Internal CRC fault from output module. The fault indicates a hardware defect or serious external interference signal.

red steady

-

Bit 3

Range fault: The default value is outside the configurated output range..

red flashes

The output is set to the maximum or minimum permissible value.

Bit 4

Reserved for internal purposes

-

-

Bit 5

Supply voltage of the RevPi AIO is below 10.2 V

red steady

The outputs are set to 0 as a safe operation cannot be guaranteed.

Bit 6

Supply voltage of the RevPi AIO is over 28.8 V.

red steady

The outputs are set to 0 as a safe operation cannot be guaranteed.

Bit 7 (MSB)

Time-out in the connection to RevPi Core (e.g. due to a PiBridge error when the piControl drive programm no longer runs properly

red steady

The outputs are set to 0. This is the presumable safe state that is also prevalent at the outputs when starting the RevPi AIO.

Status signals analog inputs

Bit 0 (MSB)

Input value is at least 20 mV or 24 µA respectively under the configured input range.

red flashes

-

Bit 1

Input value is at least 20 mV or 24 µA respectively over the configured input range.

red flashes

-

Status signals temperature input

Bit 0 (MSB)

Measured temperature is below -200 °C or a sensor short circuit.

-

-

Bit 1

Measured temperature over 850 °C or a sensor is not connected or the power supply is severed respectively.

-

-