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Showing results for tags 'network shared variable'.
Hi folks I'm working with NSV deployed in two computers (lets call them A and B), but I want to be able to make the value of the NSV in B false when the program exits in A or when this computer turns off. Any idea of how make this? PS. Excuse my english. Thanks in advance
LV2011 RT, crio-9076, using NSV's to share data back to the PC and send commands to the rio. I'm getting very slow reads of the NSV's in the RIO (on the order of 250-350ms). The shared variable engine is hosted on the RIO. I've got a critical timed loop reading from FIFO's and writing to scan engine I/O variables and reading from scan engine I/O and writing to FIFO's. I have a non-time critical communication loop that reads from NSV's and writes to FIFO's and reads from FIFO's and writes to NSV's. The time-critical loop spins like a top, 1-2ms tops in reading/writing FIFO to/from I/O vars. The reading FIFO -> writing to NSV is slow (30-40ms), but not nearly as slow as reading from NSV and writing to FIFO. Things I have tried: Disconnected typedefs from all the NSV's - this was necessary to deploy a built executable to the RIO (and have it work, that is). Some new bug in LV2011 according to NI. Changed all typedefs to variants and recast them on the RIO - this sped things up by 1/3 or so. I split the work up in subVI's for analysis purposs and the casting and writing to FIFO is very fast, it's definitely the read operation that's being pokey. Current workaround: I'm using an Updated boolean to tell the RIO when to actually read the NSV's so that my average loop time doesn't suffer so much. This works, but I want to know the why's and wherefore's of this being so slow. Further details: Exactly what I'm reading: 15 element boolean array (this is very fast by itself and I'm reading it on every loop now, not just when updated is true with no problem) 4 "position command" clusters (currently cast to variant) Enum targetEnum controlModeEnum ChannelEnum PVDouble commandDouble man controlCluster Control_ParametersEnum PV_TypeCluster PID_gainsDouble KcDouble TiDouble TdCluster Setpoint_rangeDouble highDouble lowCluster output_rangeDouble highDouble low 1 "test command" cluster (currently cast to variant)Enum trigger channelEnum trigger directionDouble lowerLimitDouble upperLimitBoolean StartBoolean Stop Those enums are 16-bit, so we're talking about 2624 bits in the 4 control clusters + 162 in the test command + 15 in the boolean array = 2801 = 350 bytes. Call it 500? with some structure padding from the cluster organization. Why would it take 300+ms to read less than 1KB of data? Best regards, Mike