BUFFER IN USE error from GPAscii

[bradp]

Hi, When I use the gpascii to load a simple program to Power PMAC active memory the second time I try to load I get an error BUFFER IN USE. A copy of my telnet session: Delta Tau Power PMAC GNU/Linux 4.0 192.168.0.200 login: root Password: ---------------------------------- -- Power PMAC 440EP bash shell -- ---------------------------------- root@192.168.0.200:/opt/ppmac# gpascii STDIN Open for ASCII Input open prog8 x50 close list prog8 X50 open prog8 stdin:4:1: error #33: BUFFER IN USE: open prog8[hr] This is a very tricky one problem. With the old Beta firmware (up to Nov 28th 2008) this will happen with PROG and PLC. In firmware after that it will happen with SUBPROG. The background to this problem is that Ppmac allows PROGs or PLC to jump to SUBPROGs (PROGs in old firmware) and use them as subroutines. This means that all PROGs and PLCs must be stopped before a SUBPROG (PROG in old firmware) can be replaced. You have the old firmware but the same problem could occur in the new firmware if you try to load a SUBPROG. What is happening to you is that the first time you load PROG8 you are just adding a new program to memory and this is allowed while other tasks run. The second time you try this you are replacing an existing program and this cannot be done unless all other PLC and PROGs are stopped. As you see in my system with old firmware and no programs running this does not happen. As soon as I start a program I get the same error. Delta Tau Power PMAC GNU/Linux 4.0 192.168.0.211 login: root Password: ---------------------------------- -- Power PMAC 440EP bash shell -- ---------------------------------- root@192.168.0.211:/opt/ppmac# gpascii STDIN Open for ASCII Input open prog8 ♠ x50 ♠ close ♠ list prog 8 X50 ♠ open prog8 ♠ x100 ♠ close ♠ list prog8 X100 ♠ enable plc 1 ♠ open prog8 stdin:12:1: error #33: BUFFER IN USE: open prog 8 ♠

[rew]

Has this problem been fixed in the latest firmware? I have Firmware 1.1.0.1, Sep 23 2009, and I need to be able to reload subprograms.

[curtwilson]

The 2010 firmware releases are more flexible (but less protective) in this regard. Previously you could not wipe out any subprogram (which is what reloading does first) if anything was running (motion program or plc program) that had the potential to call the subprogram. The new firmware does permit you to do this, putting the responsibility on you not to do anything foolish. Another requirement to provide this flexibility is that the reloaded program will be loaded at the "end" of the used memory, with a "hole" at the previous location. If you do this often enough without resetting the card, you do have the potential to hit the end of memory.