Wondering what makes the rvar rotate or stay within the limits set (EPL USB code).For example ray's code at Blue Side Up defines rvar_MCP_HDG like shown below rvar(rvar_MCP_HDG, 0, 359, 000, false); My understanding of This kind of rvar is it must rotate or else it would be very time consuming to go from 359 degrees to 000 due to the fact you must back track to get there. The syntaxusb.doc I down loaded states that if you set the wrap flag to false , the rvar will not rotate, but will stay in the specified bounds, in this example 0 thru 359. Now I'm fairly sure Ray wanted this rotary variable to rotate so I'm a little confused considering the syntax document. I wonder if the syntax doc. was a typo. Please help me get past this. EPL is my first experience with computer language and its tough to stick with it. My better half thinks I'm a nut for spending the time I have trying to learn this stuff, she just does'nt understand. Fritz

Fritz:I've never used rvars but the document clearly states if the wrap flag is set to false the rvar can't go beyond the upper limit. I can understand why some aircraft instruments wouldn't wrap-around.On the heading knob I can see requiring the pilot to turn one direction to increase the heading and the reverse direction to decrease the heading and not allow the heading knob to roll over.I'll ask Ralph Robinson if this is a typo and post the answer.

JAM01: Thank you for the reply. The way I figure is if the autopilot is flying a heading of 359 degrees and the pilot wants the autopilot to turn right just a few degrees say 010 degrees he would need to go all the way back to reach 010 if the wrap flag was set to false. If it were set to rotate the pilot would only need to turn the knob just a few degrees to the right. I noticed that Hans code for his HDG selector, the wrap flag is set to false but his comments state false allows it to rotate(things that make you go hmmmmmm). I have emailed Hans on this subject but have not received a reply as of yet. again thanks and I would be happy to hear any further info you might dig up. Fritz

Fritz:It appears the version of the Syntaxusb.doc that we both had has an error. Take a look at Ralph's response below and the new write-up on rvar.Good luck.JAM01Ralph Robinson wrote:I think the note in Syntaxusb.doc was wrong at one time.This note is correct:*************** Rotary Variables (16bit) ***************rvar(,,,,[wrap flag]);Rotary variables wrap around if the min/max limits hitexample- Rotary variable 1 with min=10 and max=359rvar(rvar1,10,359,100); if rvar1=358 and 2 added to it the new value = 10 (358+1=359, 359+1=10)If the wrap flag is set to true, the rvar will not rotate, but will stay in the specified bounds.Wrap flag default is false (wrap) <<<<<

JAM01: Thanks for going out of your way to research the wrap flag. I will downlaod the new doc. and continue to rack my brain on trying to learn EPL. I have not bought any of the Epic hardware yet. Because learning a computer language for the first time is so difficult I thought I should be sure this is within my ability before spending alot of money on Epic. Is it posible to download Epic center and compile my code without buying any of the hardware? Fritz

You can download EPICenter at http://www.flightlink.com/support/index.htmlJust ignore it when it says it can't find an EPIC.

This is a better link:http://www.flightlink.com/epic/library.html

Jam01: Thanks again. I'll try my hand at writing some code and see if it will compile. Fritz