• We recently switched our forum platform. If you experience any issues please email support@crystalfontz.com

CFA533 with HyperTerminal

gerrysc

New member
Hello,
I have a CFA533-YYH-KS unit that respons fine using 633_WinTest_1_9.exe and cftest.exe
Now I am trying to send data using the HyperTerminal, without any luck.
Is it possible someone could show me how to format a text file to send eq. "Hello World" to line 2 pos 5

There was a Thread "Visual basic and cfa-633" in 2008 with an example "try633.txt " but that link is not available anymore.

Thanks,
gerrySC
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.
 

CF Mark

Administrator
The CFA533 uses the Crystalfontz serial packet protocol.

Displaying text (or sending any other command) requires that you use the correct packet format which consists of a command number, data length, data and 16bit CRC.
In the case of displaying text, you'll need to send command number 31, the length of the text, the text data itself, and then the calculated 16bit CRC.
WinTest and cfTest create and send the command number, length and CRC data for you. When using HyperTerminal you'll need to do it yourself (not easy).

You can find more information on this under the "Host Communications" section of the CFA533 data sheet.
 

gerrysc

New member
Thanks for the answer.
Yes, you are correct, it is not easy. I have been looking at some threads in the forum talking about the packet inclding the CRC.
My project is not to use the HyperTerminal, but a micrologix 1400 PLC with the serial port communicating to the CFA533. I just thougt if I knew how to send an ascii file from the HyperTerminal, then I could figure out how to send it from the PLC.
I have communicated with Crystalfontz tech. support some months ago and they emailed me the following: Our intelligent displays with the keypads communicated over RS-232 or USB. They use a structured packet to communicate both ways; <data / command><data length><data 0><data 1>...<data n><CRC>..
At that time I had no idea what the CRC was.
In the data sheet for the CFA533 is shows examples how to calculate in "C", Java, and some others as well. My first question now is: What is the matematical formular to calculate the CRC ? And, the next: Does Crystalfontz make any displays at all that isn't using CRC for checking ?

gerrySC
 
USB LCD Displays - Graphic and Character LCDs with a Keypad

CF Mark

Administrator
Explaining the CRC function itself is too large a topic to describe in here.
Maybe these are of some help to you?
http://www.barrgroup.com/Embedded-Systems/How-To/CRC-Math-Theory
https://en.wikipedia.org/wiki/Cyclic_redundancy_check#Mathematics

As for your second question, the CFA632 and CFA634 series are serial/RS232 modules that do not use the packet protocol.
If you send a 'A' character over the serial line to the CFA632/CFA634, they will display an 'A' where the text cursor is currently located.
They have a very simple command set for blanking the display, moving the cursor, etc.

The CFA632 modules are 16x2 characters in size. The CFA634 series are 20x4 characters in size.
CFA632 product list: https://www.crystalfontz.com/search.php?q=CFA632&submit=Search
CFA634 product list: https://www.crystalfontz.com/search.php?q=CFA634&submit=Search
 

gerrysc

New member
Thanks,
I am going to purchase the CFA632 module even it doesn't have a keypad. I looked at all the modules with keypads, and as far I can see they all use the CRC packet protocol.
gerrySC
 
Top