Good Morning

I need to know how to perform,which are the steps to follow, or an example similar to this:

-An electrical equipment gives me a measure (meters)in BCD 0-3,999,999 steps or GRAY -500,00-9,999,999 steps through relays in parallel.D25-D0,i need only 16bits D0-D15 and convert to REAL.

 parallel to serial converter?

Sorry by my bad english

Thanks.

rapaga43

Good Morning

I need to know how to perform,which are the steps to follow, or an example similar to this:

-An electrical equipment gives me a measure (meters)in BCD 0-3,999,999 steps or GRAY -500,00-9,999,999 steps through relays in parallel.D25-D0,i need only 16bits D0-D15 and convert to REAL.

 parallel to serial converter?

Sorry by my bad english

Thanks.

Could you publish a technical document explaining the connections?
Thanks.

w

William_B

rapaga43

Good Morning

I need to know how to perform,which are the steps to follow, or an example similar to this:

-An electrical equipment gives me a measure (meters)in BCD 0-3,999,999 steps or GRAY -500,00-9,999,999 steps through relays in parallel.D25-D0,i need only 16bits D0-D15 and convert to REAL.

 parallel to serial converter?

Sorry by my bad english

Thanks.

Could you publish a technical document explaining the connections?
Thanks.

w

Hi there,

Thank you for the image.

Your device have many options to choose from to give you a value.
If I understand correctly, it can give display of x7 numbers.

Easy way: one signal to one input, but more expensive..... you need x26 inputs. If you have the 26 inputs the program to convert the inputs to DINT and then to REAL is not difficult - we can help you if you have problems.

Less expensive but more expensive is to use "scanning" idea where you use relays / transistors to switch input groups to the PLC.

Other idea is to make electronic circuit to convert 26 inputs to serial connection OR to 0 to 10V analog signal.

My questions..
* Do you need all 7 digits or do you need less digits?
* Do you have money to buy PLC that has 26 inputs (example CPU1212 + IN32)?

w

William_B

Hi there,

Thank you for the image.

Your device have many options to choose from to give you a value.
If I understand correctly, it can give display of x7 numbers.

	G				F				E				D				C				B				A
Biggest number	3				9				9				9				9				9				9
PINS (Dxx)			25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
Example number	1				2				3				4				5				7				9
Dxx pin OFF(0) or ON (1)			0	1	0	0	1	0	0	0	1	1	0	1	0	0	0	1	0	1	0	1	1	1	1	0	0	1

Easy way: one signal to one input, but more expensive..... you need x26 inputs. If you have the 26 inputs the program to convert the inputs to DINT and then to REAL is not difficult - we can help you if you have problems.

Less expensive but more expensive is to use "scanning" idea where you use relays / transistors to switch input groups to the PLC.

Other idea is to make electronic circuit to convert 26 inputs to serial connection OR to 0 to 10V analog signal.

My questions..
* Do you need all 7 digits or do you need less digits?
* Do you have money to buy PLC that has 26 inputs (example CPU1212 + IN32)?

w

thank you very much william

I need 5 digits ( 000,00 - 999,99) meters above sea level, a range of 60 meters.

Examples 1 and 2 are ok, 3 i have no time to make.

might get example of first please? would be with MD...double word

thanks

rapaga43

thank you very much william

I need 5 digits ( 000,00 - 999,99) meters above sea level, a range of 60 meters.

Examples 1 and 2 are ok, 3 i have no time to make.

might get example of first please? would be with MD...double word

thanks

Maybe the following solution will work for you..

(continue)

FUNCTION_BLOCK "Convert_BCD_inputs"
TITLE = CONVERT BCD INPUTS TO REAL NUMBER

AUTHOR : WilliamB
FAMILY : Forum
VERSION : 0.1

   VAR_INPUT
      REAL_scaling : Real := 1.0;   // Scaling factor used by REAL number conversion
      D00 : Bool := FALSE;   // Digital input pin 1 of 32
      {more}
      D31 : Bool := FALSE;   // Digital input pin 32 of 32
   END_VAR

   VAR_OUTPUT
      BCD_value : DWord;   // Binary bits converted to a BCD number
      DINT_value : DInt;
      REAL_value : Real;
   END_VAR

   VAR_TEMP
      construct : DWord;   // Construct a DWORD from individual bits
      result : DInt;   // Temporary result
   END_VAR


BEGIN
    // Construct a DWORD from 32 individual bits
    #construct.%X0 := #D00;
    {more}
    #construct.%X31 := #D31;
   
    // Code block outfeed - BCD number in a DWORD
    #BCD_value := #construct;
   
    // BCD number to bit encoded DINT number
    #result := BCD32_TO_DINT(IN := #construct);
    #DINT_value := #result;
   
    // DINT number converted to REAL with indicated factor
    #REAL_value := DINT_TO_REAL(IN := #result) * #REAL_scaling;
   
END_FUNCTION_BLOCK

The code provides the ability for you to "connect" up to 32 individual inputs onto the FB. The FB can then convert the inputs to BCD or DINT or REAL. A picture shows how you would use it (guessing). It is assumed that you use individual inputs from the PLC and that you use the BCD setting on your device.

The SCL file is the one that you can import into your PLC project - provided that you have TIA V13.

Please consider rating this posting with stars.. if it is worth something to you. (wink)

Question are also welcome.
w

William_B

Hi,

If we could ignore the negative numbers and we need to represent seven digits,  then 17 bits ( digital inputs) are needed. The 17 bits can represent maximum integer number of 131,070. Notice that the 16-bit unsigned number goes to 65,535.

So the question: Does your REAL measurement go beyond 655.35; do you really need to go up to 999.99?

Hi,

I don´t know if i have understood you,i need  to measure a range( 59 meters),for example 308 meters above sea level to 367 meters,being the 0% 308m y 100% 367m.

i don´t use the negative numbers, i need 308,000 digits,then should i use 17 bits?

I hope i explained

thanks for your explanations and your time.

rapaga43

 Hi,

I don´t know if i have understood you,i need  to measure a range( 59 meters),for example 308 meters above sea level to 367 meters,being the 0% 308m y 100% 367m.

i don´t use the negative numbers, i need 308,000 digits,then should i use 17 bits?

I hope i explained

thanks for your explanations and your time.

Hi.

Does the instrument give out a number in meters or in 10mm increments?
I am having trouble understanding the consistency of your facts.
Please help me with this..

-------------------
Earlier you said:
I need 5 digits ( 000,00 - 999,99) meters above sea level,
a range of 60 meters.

From these words I understand
a) You use the coma "," as decimal indicator in your country.
         (I use a point "." to indicate the decimal position.)

b) You wish to measure absolute height of [000.00 .. 999.99]m.
you require to convert a 5 digit number.

c) The absolute height you measure is in increments of 0.01m.
The instrument gives a number of increments.
The PLC needs to have a REAL where 1.0 >> 1m.

d) From the absolute measurements the span will be 60m.
-----------------------------

Now you are saying 308m >>>  308 000 on the instrument.
a) The absolute height is measured in increments of 0.001m

b) You require 6 digits.. not 5 digits.

...  308 000 as BINARY encoded number needs 18 bits.
     18 bits can give a number up to 327 679

...  308 000 as BCD encoded number needs 6 x 4 = 24 bits.
      The biggest number yo will be able to measure is 999 999.
      The PLC code I have provided by now will also work.
-----------------------------

Questions

* How many digits do you get from the measurement instrument?

* Which of the assumptions are correct and which are wrong?

* Do you want to work with a BINARY encoded number
or BCD encoded number?

* What resolution do you need from the measurement device
      - 0.001m or 0.01m or something else?
-----------------------------

EXAMPLE                     6 digits on instrument by 5 digits to PLC

(a) Device gives out a measurement value in 0.001m increments (6 digits).
(b) The PLC only needs resolution of 0.01m.
(c) BCD encoded number is used.
(d) You are using 20 bits (pins D04 to D23)

Example solution when using FB80 example (see ZIP):
D00 to D03 <=  false
D04 to D23 <=  I2.0 to I3.7

Does all this writing make sense to you?
w