E-Bus Analog I/O Data Representation
The limit with the largest value is used as the Full Scale Value for current and voltage measurement in analog I/O devices. It is represented by the decimal value +32767 (hex: 0x7FFF).
The bit resolution shown in the product Description (see following image) states the resolution of the digital-to-analog and analog-to-digital converters used in the product, not the data range of the values. This means that the device may not be able to differentiate between two values, i.e. the analog output behavior will be identical for two different user or application-specified values such as 0 and 3; the analog devices will output 0V for both 0 and 3.
For example, the AKT2G-AT-410 is a 0-10V device with 12-bit resolution. The digital converted data output from this device is a 15-bit resolution (with signed data representation), which results in a loss of 3-bits representation. If you feed a signal voltage of 0.00122 V (which is read as 4 digitally) then output reading will show this value as 0V.
Analog input thermocouple devices represent 0°C as a data value of 0. Each increment of the data value represents a 0.1°C increment in measured temperature. This means the widest data range of values for the thermocouple devices is from decimal values -2000 to +13700, representing -200°C and +1370°C respectively.
Analog Output Signal Table
Value | Output Signal | ||
---|---|---|---|
Decimal | Hexadecimal | AKT2G-AT-410, AKT2G-AT--810 | AKT2G-AT-425 |
32767 | 0x7FFF | 10V | 10V |
16383 | 0x3FFF | 5V | 5V |
16 | 0x0010 | 0.00488V | 0.00488V |
8 | 0x0008 | 0.00244V | 0.00244V |
1 | 0x0001 | 0V (limited by 12-bit resolution on DAC) | ... |
0 | 0V | 0V | |
-1 | 0xFFFF | out-of-range | ... |
-8 | 0xFFF8 | 0V (limited by 12-bit resolution on DAC) | |
-16 | 0xFFF0 | ... | -0.00488V |
-16838 | 0xC001 | -5V | |
-32768 | 0x8000 | out-of-range | -10V |
Analog Input Signal Table
Input Signal | Value | |||
---|---|---|---|---|
AKT2G-AN-200, AKT2G-AN-400, AKT2G-AN-440 |
AKT2G-AN-240 (temperature mode) |
AKT2G-AN-430 | Decimal | Hexadecimal |
out-of-range | out-of-range | 10V or 20mA | 32767 | 0x7FFF |
out-of-range | out-of-range | 5V or 10mA | 16383 | 0x3FFF |
1370.0°C | 1370.0°C | ... | 13700 | 0x3584 |
0.1°C | 0.1°C | 0.0003V or 0.0006mA | 1 | 0x0001 |
0°C | 0°C | 0V or 0mA | 0 | |
-0.1°C | -0.1°C | -0.0003V or -0.0006mA | -1 | 0xFFFF |
-200.0°C | -200.0°C | ... | -2000 | 0xF830 |
out-of-range | out-of-range | -5V or -10mA | -16838 | 0xC001 |
out-of-range | out-of-range | -10V or -20mA | -32768 | 0x8000 |