Unprotected Read in PLC-5

[laisp]

You cannot use the Unprotected Read to read any other data file except the one you have designated as the PLC-2 compatibility file.

Seriously ? I can't use unprotected read to read any file but only a designated file where only information in there could be read?

Thanks Again!

 

[laisp]

Thank you all for helping me with this, I did a bit further reading and noticed the unprotected read does require a special file to be registered in it first before imitating the read sequence, I guess that option is not possible then so I did further reading and noticed maybe the typed read could do the trick? Since I could perform masking on the other end.

But then again what is Packet Offset, Total Trans and PLC-5 Sys.address?

Please refer to attachment, thank you!

 

[Mark-]

Hello,

>But then again what is Packet Offset,

The answer is in the document. Contains the offset from the address in the address field.

For PLC5 we use Word Range Read.

 

[laisp]

Hello,

>But then again what is Packet Offset,

The answer is in the document. Contains the offset from the address in the address field.

For PLC5 we use Word Range Read.

Just started reading this word range (read block) command I guess it could do the trick as well, just curious as to what is the PLC Sys.Address same as before ? Logical Addressing? ? I couldn't understand what is Packet Offset and Total Trans....is there an example of it somewhere? Thanks Again!

 

[Mark-]

Hello,

Yes, the answer are in the manual and there are some examples. Use the search and seek out the words you do not understand.

 

[laisp]

Hello,

Yes, the answer are in the manual and there are some examples. Use the search and seek out the words you do not understand.

Thanks, I think I just noticed the word range read does not support floats, guess I have to go back to Typed read/write...
if I only read/write one word at a time does that mean the PACKET OFFSET should be 00 00 and the TOTAL TRANS would be 00 0F Hex? Or am I missing something here...

 

[Ken Roach]

I recommend starting a new thread discussing which DF1 command codes are appropriate for the driver your Company is writing. You can get input on which ones work with the datatypes and controllers you want to access, and how exactly those commands work.

The Unprotected Read and Unprotected Write really do only allow access to that one specifically defined data table. In the PLC-5 they call it the "PLC-2 compatibility table" and in the SLC they call it a "Compatibility Interface File" (I think that's what CIF means).

That data file is a pure 16-bit address space. You could theoretically pack 32-bit datatypes like a Float in there and unpack them on the other side, but it definitely does not provide a simple way to read anything but 16-bit integers.

 

[Mark-]

Hello,

>I just noticed the word range read does not support floats

Yes it does. What makes you think it does not?