Calibration
Vendor calibration
The electrical channel is calibrated by Beckhoff in the "Vendor Calibration" functional unit for compliance with the specified uncertainty (see Technical data, previously: Measuring error). The vendor calibration data from Beckhoff is available in this area.
Parameters:
Index (hex) | Name | Data Type | Meaning |
|---|---|---|---|
80n0:0B | Enable vendor calibration | BOOL | enabled by default, the data is taken into account. |
80nF | Vendor calibration data | - | not intended for user modification |
The intermediate value after this functional unit can be viewed in index 0x90n0:1C "Value after Calibration". There is only one common Value after Calibration for all calibration values, in which all calibration values are displayed offset against the measured value.
The number of setting changes in this functional unit is counted up in index 0x90n2:11 as "Vendor Calibration Counter".
If any parameter in the data area is changed, the counter is incremented. Further changes in the data area within the next 30 seconds are not taken into account for the counter. After this time has elapsed, a parameter change will increment the counter again.
User calibration
The "User calibration" functional unit can be used by the user if alternative, system-dependent correction values are to be used permanently.
The gain/offset coefficients are available both in Real32 format for convenient operation and alternatively (but with the same mathematical effect) in INT16 format for compatibility with any existing code. Processing in "User Calibration" (if "Enable User calibration" = 1) is as follows:
- for setpoint >= 0: "Value after User calibration" = S0 + "Value after Vendor calibration" * S1 +("Value after Vendor calibration")² * S2
- for setpoint < 0: "Value after User calibration" = S0 + "Value after Vendor calibration" * S1n +("Value after Vendor calibration")² * S2
Parameters:
Index (hex) | Name | Data Type | Meaning |
|---|---|---|---|
80n0:0A | Enable user calibration | BOOL | disabled by default, calculation only takes place if TRUE |
80n0:17 | User calibration Offset | SINT16 | 1 Bit = FSVnorm./32767, default: 0 |
80n0:18 | User calibration Gain | UINT16 | 1 bit corresponds to 2-16, so "1" corresponds to 0x7FFF/32767dec |
80nC:01 | User calibration Data | BYTE4 | 4 bytes of free memory space; here it is possible to store the calibration date in the form of 8 CHAR, for example |
80nC:03…0D | User Scale Gain (Real32) | REAL32 | Real32 coefficients S0/S1/S2/S3/S1n of the calculation polynomial |
The intermediate value after this functional unit can be viewed in index 0x9nn0:1C "Value after Calibration". There is only one common Value after Calibration for all calibration values, in which all calibration values are displayed offset against the measured value.
The number of setting changes in this functional unit is counted up in index 0x90n2:12 "User Calibration Counter".
If any parameter in the data area is changed, the counter is incremented. Further changes in the data area within the next 30 seconds are not taken into account for the counter. After this time has elapsed, a parameter change will increment the counter again.
Password protection for user data
Some user data are protected against unwanted or inadvertent writing by an additional password to be entered in CoE 0xF009:
- CoE write accesses by the user, PLC or startup entries in Single or CompleteAccess mode
- Overwrite the values by RestoreDefaultParameter Access to 0x80n0 (or 0x80nD, if available)
Fig.23: Password protection for the 0x8000:17 and 0x8000:18 entries (example)Use of CoE 0xF009
- Entering 0x12345678 enables the password protection → Object shows "1" (enabled)
Protected objects can now no longer be changed, no error message occurs during a write access! - Entering 0x11223344 disables password protection → Object displays "0" (disabled)
Password protection takes effect with the following AI settings:
Index (hex) | Designation |
|---|---|
80n0:0A | Enable User calibration |
80n0:0B | Enable Vendor calibration |
80n0:17 | User calibration offset |
80n0:18 | User calibration gain |
80nC | User calibration Data |
80nD:17 | Low Range Error |
80nD:18 | High Range Error |
80nD:27 | Low Range Error (REAL32) |
80nD:28 | High Range Error (REAL32) |