notear_guy
Member
hi there!im a neophyte of plc.could anyone over there could explain to me how btr/btw work?pls. do give example.thanks and best regards.
btr/btw problem
- Thread starter notear_guy
- Start date
rsdoran
Lifetime Supporting Member
Another example of a bad question.
PLCs do not have the same instructions; therefore you should state the PLC.
BTR/BTW is AB specific; Blcok transfer read and Block Transfer Write examples can be found here: http://domino.automation.rockwell.com/applications/kb/RAKB.nsf/$$Search?OpenForm&Seq=1
PLCs do not have the same instructions; therefore you should state the PLC.
BTR/BTW is AB specific; Blcok transfer read and Block Transfer Write examples can be found here: http://domino.automation.rockwell.com/applications/kb/RAKB.nsf/$$Search?OpenForm&Seq=1
randylud
Member
Your question is pretty broad so a really good answer is kind of hard to put together. BTW/BTR are communications protocols used in various Allen-Bradley processors. This comms method is slightly different depending on which processor family or version you are using. But, in general, the BTW/BTR functions are used to transmit blocks of as much as 64 words of data between a processor and some remote I/O device. This is most often done via the RIO module and the device or rack connected as remote communicates to the processor via this link. The words of data can literally be any words, but are often real I/O bits or words used for remote I/O modules in remote racks. Now, if there is a device such as a PanelView or some other product connected to the link the words can be most anything from data to bits that represent push buttons on the PanelView screen or things that need to be turned on or off on the screen. There are a vast array of possibilities here so some additional detail on your part would be helpful. Also, if you are indeed the neophyte that you claim to be, this is going get to be a bit difficult for you initially. Go to http://domino.automation.rockwell.com/applications/kb/RAKB.nsf/$$Search/?OpenForm and search for topics related to the BTW/BTR process, this will give you more specific details!
Ron Beaufort
Lifetime Supporting Member
this is one of those subjects where "general" information is pretty useless ... you've got to be specific in order to get helpful information ...
if it's an Allen-Bradley PLC-5, then this post might help with the basic ideas ... if you need more than this, tell us whether you're using N-type or BT-type control blocks ...
if it's an Allen-Bradley SLC-5xx, then things will be different ... in that case we'll need to know exactly what model processor - and what OS (Operating System - example OS401) the processor is using ... it would also be helpful to know exactly what type of device you're going to be communicating with ...
if it's an Allen-Bradley PLC-5, then this post might help with the basic ideas ... if you need more than this, tell us whether you're using N-type or BT-type control blocks ...
if it's an Allen-Bradley SLC-5xx, then things will be different ... in that case we'll need to know exactly what model processor - and what OS (Operating System - example OS401) the processor is using ... it would also be helpful to know exactly what type of device you're going to be communicating with ...
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