Cdios 6152 Controller Commands 

This command reads/writes A/D converter and calibration values.
 

Command	Module ID	3	4	5	6	7	8
2Fh	0 - 15	Selector	Data or zero (lsb)         (msb)		0	0	0

Parameter	Value	Description	Data in Command	Data in Reply
Selector	00h 01h 02h 03h	Read Offset calibration value of input #1 Write Offset calibration value of input #1 Read Full-scale calibration value of  input #1 Write Full-scale calibration value of  input #1	- X - X	X - X -
	10h 11h 12h 13h	Read Offset calibration value of input #2 Write Offset calibration value of input #2 Read Full-scale calibration value of  input #2 Write Full-scale calibration value of  input #2	- X - X	X - X -
	20h 21h 22h 23h	Read Offset calibration value of input #3 Write Offset calibration value of input #3 Read Full-scale calibration value of  input #3 Write Full-scale calibration value of  input #3	- X - X	X - X -
	FBh	Read self-calibrated A/D converter Offset	-	X
	FCh	Read self-calibrated A/D converter Gain	-	X
	FDh	Stop calibration measurements. After this, the 6163  has to be re-initialized because sample rate, number of channels and filter settings may have changed.	-	-
	FEh	Setup for calibration measurements: Basic sample rate set to 60Hz. Measured channels set to 4. Offsets set to zero. Gains set to one. Filters set to maximum.	-	-
	FFh	Same as FEh, but Basic sample rate = 50Hz	-	-

Normal reply is:

 

Reply	Module ID	3	4	5	6	7	8
2Fh	0 - 15	Selector (copy of command)	Data or zero (lsb)        (msb)		0	0	0

 Possible error message:

 

Error	Module ID	3	4	5	6	7	8
AFh	0 - 15	0	0	Error Status	0	0	0

Parameter	Bit	Description
Error status	0 1 2	1 = Selector parameter out of range 1 = Calibration value write sequence error (data ignored) 1 = FLASH EPROM programming failed

 

1. If not all 6 calibration factors are to be adjusted; first read the calibration values that are to be left unchanged and store them in the calibration table (because ALL values have to be written....).

    

2. Initialize the A/D converter with command 2Fh, Selector code FEh or FFh, to measure 3 channels at a 50 or 60Hz converter sample rate, with maximum filter setting.

    

3. Use a 'dummy' Loadcell (e.g. two 1K resistors in series), connect this to Input 1:
   • Single end of first resistor to V+
   • Intersection of both resistors to +In and -In
   • Single end of second resistor to Gnd

      

4. Measure all 3 input offset values:
   • Wait 2 seconds for the input filters to stabilize
   • Read value with a 'Read analog inputs' command (28h).
   • Store the Input value as Offset value in the calibration table.

      

5. Use a fixed reference 'dummy' Loadcell of approx. 2mV/V to input 1 (e.g. three very low tempco. resistors, R1 = R3 = 2K49, R2 = 10E). Determine the exact value of this 'loadcell'.
   • Single end of R1 to V+
   • Intersection of R1/R2 to +In
   • Intersection of R2/R3 to -In
   • Single end of R3 to Gnd

      

6. Measure all 3 input full-scale values:
   • Wait 2 seconds for the input filters to stabilize.
   • Read value with a 'Read analog inputs' command (28h).
   • Calculate new 16 bits Full-scale value, so that a 2mV/V input will generate 30000 as A/D value.
     Calculation should be done with at least single precision floating point arithmetic, rounded to unsigned integer.
     
     Full-scale value =   Loadcell Value * 15000 / (Input value - Offset value) *  8000h
     
     Full-scale value =  Loadcell Value / (Input value - Offset value) *  491520000
     
     Store this Full-scale value in the calibration table.

      

7. Write all 6 calibration values from the table to the 6163:
   • Writing must be done in ascending order (command 2Fh, Selector codes: 01h, 03h, 11h, 13h, 21h and 23h), otherwise the 6163 will return the 'Calibration value write sequence error'.
     The data is internally buffered by the 6163 in RAM.

      

   • There must be an maximum delay of 100 mS between two write commands, otherwise the next calibration write command will return the 'Calibration value write sequence error'.

      

   • After the last write command (2Fh, Selector code 23h), the 6163 erases the calibration FLASH EPROM and writes the new values. This can take up to 500 milli-seconds before the 6163 sends a reply or error message.

      

8. Send the 'Reset 6163' Command (2Fh, Selector code FDh) to resume normal operation