C/C++ - Industrial Dual 0-20mA Bricklet

This is the description of the C/C++ API bindings for the Industrial Dual 0-20mA Bricklet. General information and technical specifications for the Industrial Dual 0-20mA Bricklet are summarized in its hardware description.

An installation guide for the C/C++ API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Simple

Download (example_simple.c)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
#include <stdio.h>

#include "ip_connection.h"
#include "bricklet_industrial_dual_0_20ma.h"

#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Industrial Dual 0-20mA Bricklet

int main(void) {
    // Create IP connection
    IPConnection ipcon;
    ipcon_create(&ipcon);

    // Create device object
    IndustrialDual020mA id020;
    industrial_dual_0_20ma_create(&id020, UID, &ipcon);

    // Connect to brickd
    if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
        fprintf(stderr, "Could not connect\n");
        return 1;
    }
    // Don't use device before ipcon is connected

    // Get current current from sensor 1
    int32_t current;
    if(industrial_dual_0_20ma_get_current(&id020, 1, &current) < 0) {
        fprintf(stderr, "Could not get current from sensor 1, probably timeout\n");
        return 1;
    }

    printf("Current (Sensor 1): %f mA\n", current/1000000.0);

    printf("Press key to exit\n");
    getchar();
    industrial_dual_0_20ma_destroy(&id020);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

Callback

Download (example_callback.c)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
#include <stdio.h>

#include "ip_connection.h"
#include "bricklet_industrial_dual_0_20ma.h"

#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Industrial Dual 0-20mA Bricklet

// Callback function for current callback
void cb_current(uint8_t sensor, int32_t current, void *user_data) {
    (void)user_data; // avoid unused parameter warning

    printf("Sensor: %u\n", sensor);
    printf("Current: %f mA\n", current/1000000.0);
    printf("\n");
}

int main(void) {
    // Create IP connection
    IPConnection ipcon;
    ipcon_create(&ipcon);

    // Create device object
    IndustrialDual020mA id020;
    industrial_dual_0_20ma_create(&id020, UID, &ipcon);

    // Connect to brickd
    if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
        fprintf(stderr, "Could not connect\n");
        return 1;
    }
    // Don't use device before ipcon is connected

    // Register current callback to function cb_current
    industrial_dual_0_20ma_register_callback(&id020,
                                             INDUSTRIAL_DUAL_0_20MA_CALLBACK_CURRENT,
                                             (void *)cb_current,
                                             NULL);

    // Set period for current (sensor 1) callback to 1s (1000ms)
    // Note: The current (sensor 1) callback is only called every second
    //       if the current (sensor 1) has changed since the last call!
    industrial_dual_0_20ma_set_current_callback_period(&id020, 1, 1000);

    printf("Press key to exit\n");
    getchar();
    industrial_dual_0_20ma_destroy(&id020);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

Threshold

Download (example_threshold.c)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
#include <stdio.h>

#include "ip_connection.h"
#include "bricklet_industrial_dual_0_20ma.h"

#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Industrial Dual 0-20mA Bricklet

// Callback function for current reached callback
void cb_current_reached(uint8_t sensor, int32_t current, void *user_data) {
    (void)user_data; // avoid unused parameter warning

    printf("Sensor: %u\n", sensor);
    printf("Current: %f mA\n", current/1000000.0);
    printf("\n");
}

int main(void) {
    // Create IP connection
    IPConnection ipcon;
    ipcon_create(&ipcon);

    // Create device object
    IndustrialDual020mA id020;
    industrial_dual_0_20ma_create(&id020, UID, &ipcon);

    // Connect to brickd
    if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
        fprintf(stderr, "Could not connect\n");
        return 1;
    }
    // Don't use device before ipcon is connected

    // Get threshold callbacks with a debounce time of 10 seconds (10000ms)
    industrial_dual_0_20ma_set_debounce_period(&id020, 10000);

    // Register current reached callback to function cb_current_reached
    industrial_dual_0_20ma_register_callback(&id020,
                                             INDUSTRIAL_DUAL_0_20MA_CALLBACK_CURRENT_REACHED,
                                             (void *)cb_current_reached,
                                             NULL);

    // Configure threshold for current (sensor 1) "greater than 10 mA"
    industrial_dual_0_20ma_set_current_callback_threshold(&id020, 1, '>', 10*1000000, 0);

    printf("Press key to exit\n");
    getchar();
    industrial_dual_0_20ma_destroy(&id020);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

API

Every function of the C/C++ bindings returns an integer which describes an error code. Data returned from the device, when a getter is called, is handled via call by reference. These parameters are labeled with the ret_ prefix.

Possible error codes are:

  • E_OK = 0
  • E_TIMEOUT = -1
  • E_NO_STREAM_SOCKET = -2
  • E_HOSTNAME_INVALID = -3
  • E_NO_CONNECT = -4
  • E_NO_THREAD = -5
  • E_NOT_ADDED = -6 (unused since bindings version 2.0.0)
  • E_ALREADY_CONNECTED = -7
  • E_NOT_CONNECTED = -8
  • E_INVALID_PARAMETER = -9
  • E_NOT_SUPPORTED = -10
  • E_UNKNOWN_ERROR_CODE = -11
  • E_STREAM_OUT_OF_SYNC = -12

as defined in ip_connection.h.

All functions listed below are thread-safe.

Two sensors can be connected to the Bricklet. Functions that are related directly to a sensor have a sensor parameter to specify one of the two sensors. Valid values for the sensor parameter are 0 and 1.

Basic Functions

void industrial_dual_0_20ma_create(IndustrialDual020mA *industrial_dual_0_20ma, const char *uid, IPConnection *ipcon)

Creates the device object industrial_dual_0_20ma with the unique device ID uid and adds it to the IPConnection ipcon:

IndustrialDual020mA industrial_dual_0_20ma;
industrial_dual_0_20ma_create(&industrial_dual_0_20ma, "YOUR_DEVICE_UID", &ipcon);

This device object can be used after the IP connection has been connected (see examples above).

void industrial_dual_0_20ma_destroy(IndustrialDual020mA *industrial_dual_0_20ma)

Removes the device object industrial_dual_0_20ma from its IPConnection and destroys it. The device object cannot be used anymore afterwards.

int industrial_dual_0_20ma_get_current(IndustrialDual020mA *industrial_dual_0_20ma, uint8_t sensor, int32_t *ret_current)

Returns the current of the specified sensor (0 or 1). The value is in nA and between 0nA and 22505322nA (22.5mA).

It is possible to detect if an IEC 60381-1 compatible sensor is connected and if it works probably.

If the returned current is below 4mA, there is likely no sensor connected or the sensor may be defect. If the returned current is over 20mA, there might be a short circuit or the sensor may be defect.

If you want to get the current periodically, it is recommended to use the INDUSTRIAL_DUAL_0_20MA_CALLBACK_CURRENT callback and set the period with industrial_dual_0_20ma_set_current_callback_period().

Advanced Functions

int industrial_dual_0_20ma_set_sample_rate(IndustrialDual020mA *industrial_dual_0_20ma, uint8_t rate)

Sets the sample rate to either 240, 60, 15 or 4 samples per second. The resolution for the rates is 12, 14, 16 and 18 bit respectively.

Value Description
0 240 samples per second, 12 bit resolution
1 60 samples per second, 14 bit resolution
2 15 samples per second, 16 bit resolution
3 4 samples per second, 18 bit resolution

The default value is 3 (4 samples per second with 18 bit resolution).

The following defines are available for this function:

  • INDUSTRIAL_DUAL_0_20MA_SAMPLE_RATE_240_SPS = 0
  • INDUSTRIAL_DUAL_0_20MA_SAMPLE_RATE_60_SPS = 1
  • INDUSTRIAL_DUAL_0_20MA_SAMPLE_RATE_15_SPS = 2
  • INDUSTRIAL_DUAL_0_20MA_SAMPLE_RATE_4_SPS = 3
int industrial_dual_0_20ma_get_sample_rate(IndustrialDual020mA *industrial_dual_0_20ma, uint8_t *ret_rate)

Returns the sample rate as set by industrial_dual_0_20ma_set_sample_rate().

The following defines are available for this function:

  • INDUSTRIAL_DUAL_0_20MA_SAMPLE_RATE_240_SPS = 0
  • INDUSTRIAL_DUAL_0_20MA_SAMPLE_RATE_60_SPS = 1
  • INDUSTRIAL_DUAL_0_20MA_SAMPLE_RATE_15_SPS = 2
  • INDUSTRIAL_DUAL_0_20MA_SAMPLE_RATE_4_SPS = 3
int industrial_dual_0_20ma_get_api_version(IndustrialDual020mA *industrial_dual_0_20ma, uint8_t ret_api_version[3])

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

int industrial_dual_0_20ma_get_response_expected(IndustrialDual020mA *industrial_dual_0_20ma, uint8_t function_id, bool *ret_response_expected)

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by industrial_dual_0_20ma_set_response_expected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

See industrial_dual_0_20ma_set_response_expected() for the list of function ID defines available for this function.

int industrial_dual_0_20ma_set_response_expected(IndustrialDual020mA *industrial_dual_0_20ma, uint8_t function_id, bool response_expected)

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following function ID defines are available for this function:

  • INDUSTRIAL_DUAL_0_20MA_FUNCTION_SET_CURRENT_CALLBACK_PERIOD = 2
  • INDUSTRIAL_DUAL_0_20MA_FUNCTION_SET_CURRENT_CALLBACK_THRESHOLD = 4
  • INDUSTRIAL_DUAL_0_20MA_FUNCTION_SET_DEBOUNCE_PERIOD = 6
  • INDUSTRIAL_DUAL_0_20MA_FUNCTION_SET_SAMPLE_RATE = 8
int industrial_dual_0_20ma_set_response_expected_all(IndustrialDual020mA *industrial_dual_0_20ma, bool response_expected)

Changes the response expected flag for all setter and callback configuration functions of this device at once.

int industrial_dual_0_20ma_get_identity(IndustrialDual020mA *industrial_dual_0_20ma, char ret_uid[8], char ret_connected_uid[8], char *ret_position, uint8_t ret_hardware_version[3], uint8_t ret_firmware_version[3], uint16_t *ret_device_identifier)

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions

void industrial_dual_0_20ma_register_callback(IndustrialDual020mA *industrial_dual_0_20ma, int16_t callback_id, void *function, void *user_data)

Registers the given function with the given callback_id. The user_data will be passed as the last parameter to the function.

The available callback IDs with corresponding function signatures are listed below.

int industrial_dual_0_20ma_set_current_callback_period(IndustrialDual020mA *industrial_dual_0_20ma, uint8_t sensor, uint32_t period)

Sets the period in ms with which the INDUSTRIAL_DUAL_0_20MA_CALLBACK_CURRENT callback is triggered periodically for the given sensor. A value of 0 turns the callback off.

The INDUSTRIAL_DUAL_0_20MA_CALLBACK_CURRENT callback is only triggered if the current has changed since the last triggering.

The default value is 0.

int industrial_dual_0_20ma_get_current_callback_period(IndustrialDual020mA *industrial_dual_0_20ma, uint8_t sensor, uint32_t *ret_period)

Returns the period as set by industrial_dual_0_20ma_set_current_callback_period().

int industrial_dual_0_20ma_set_current_callback_threshold(IndustrialDual020mA *industrial_dual_0_20ma, uint8_t sensor, char option, int32_t min, int32_t max)

Sets the thresholds for the INDUSTRIAL_DUAL_0_20MA_CALLBACK_CURRENT_REACHED callback for the given sensor.

The following options are possible:

Option Description
'x' Callback is turned off
'o' Callback is triggered when the current is outside the min and max values
'i' Callback is triggered when the current is inside the min and max values
'<' Callback is triggered when the current is smaller than the min value (max is ignored)
'>' Callback is triggered when the current is greater than the min value (max is ignored)

The default value is ('x', 0, 0).

The following defines are available for this function:

  • INDUSTRIAL_DUAL_0_20MA_THRESHOLD_OPTION_OFF = 'x'
  • INDUSTRIAL_DUAL_0_20MA_THRESHOLD_OPTION_OUTSIDE = 'o'
  • INDUSTRIAL_DUAL_0_20MA_THRESHOLD_OPTION_INSIDE = 'i'
  • INDUSTRIAL_DUAL_0_20MA_THRESHOLD_OPTION_SMALLER = '<'
  • INDUSTRIAL_DUAL_0_20MA_THRESHOLD_OPTION_GREATER = '>'
int industrial_dual_0_20ma_get_current_callback_threshold(IndustrialDual020mA *industrial_dual_0_20ma, uint8_t sensor, char *ret_option, int32_t *ret_min, int32_t *ret_max)

Returns the threshold as set by industrial_dual_0_20ma_set_current_callback_threshold().

The following defines are available for this function:

  • INDUSTRIAL_DUAL_0_20MA_THRESHOLD_OPTION_OFF = 'x'
  • INDUSTRIAL_DUAL_0_20MA_THRESHOLD_OPTION_OUTSIDE = 'o'
  • INDUSTRIAL_DUAL_0_20MA_THRESHOLD_OPTION_INSIDE = 'i'
  • INDUSTRIAL_DUAL_0_20MA_THRESHOLD_OPTION_SMALLER = '<'
  • INDUSTRIAL_DUAL_0_20MA_THRESHOLD_OPTION_GREATER = '>'
int industrial_dual_0_20ma_set_debounce_period(IndustrialDual020mA *industrial_dual_0_20ma, uint32_t debounce)

Sets the period in ms with which the threshold callback

is triggered, if the threshold

keeps being reached.

The default value is 100.

int industrial_dual_0_20ma_get_debounce_period(IndustrialDual020mA *industrial_dual_0_20ma, uint32_t *ret_debounce)

Returns the debounce period as set by industrial_dual_0_20ma_set_debounce_period().

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the industrial_dual_0_20ma_register_callback() function. The parameters consist of the device object, the callback ID, the callback function and optional user data:

void my_callback(int p, void *user_data) {
    printf("parameter: %d\n", p);
}

industrial_dual_0_20ma_register_callback(&industrial_dual_0_20ma, INDUSTRIAL_DUAL_0_20MA_CALLBACK_EXAMPLE, (void *)my_callback, NULL);

The available constants with corresponding callback function signatures are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

INDUSTRIAL_DUAL_0_20MA_CALLBACK_CURRENT
void callback(uint8_t sensor, int32_t current, void *user_data)

This callback is triggered periodically with the period that is set by industrial_dual_0_20ma_set_current_callback_period(). The parameter is the current of the sensor.

The INDUSTRIAL_DUAL_0_20MA_CALLBACK_CURRENT callback is only triggered if the current has changed since the last triggering.

INDUSTRIAL_DUAL_0_20MA_CALLBACK_CURRENT_REACHED
void callback(uint8_t sensor, int32_t current, void *user_data)

This callback is triggered when the threshold as set by industrial_dual_0_20ma_set_current_callback_threshold() is reached. The parameter is the current of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by industrial_dual_0_20ma_set_debounce_period().

Constants

INDUSTRIAL_DUAL_0_20MA_DEVICE_IDENTIFIER

This constant is used to identify a Industrial Dual 0-20mA Bricklet.

The industrial_dual_0_20ma_get_identity() function and the IPCON_CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

INDUSTRIAL_DUAL_0_20MA_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Industrial Dual 0-20mA Bricklet.