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Showing results for tags 'RS485'.
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An output power display for my solar system. G2553 Launchpad, Blue 4-digit LED display, RS485 Transceiver SN65HVD12P (a low power, 3.3V version of the standard SN75176), this is all there is. All pins are used, 4 + 7 for the multiplexed LEDs (no resistors: Blue LED, 3.6V supply, output resistance of the pins limit the LED current) 3 pins for UART and send/receive for the SN65. 2 pins for 32768Hz xtal (I had this one soldered in on the LP, so why not use it) The MSP asks the inverter over RS485/Modbus "what is your current output power". After less than half a sec, the inverter aswers with the required value. This repeats every 2 seconds. The inverter is a Fronius Symo, with Datamanager 2 (which I guess is an embedded linux machine, covering LAN, Wifi, Modbus.....). The communication protocol can be downloaded from the Fronius website (after signing in), so no reverse engineering was required. Instead of only power, I could also display line voltage, frequency, total delivered energy.... This is just a working prototype on Launchpad, I will do a PCB later, I also plan to power this directly from the inverter (which has a 12V solar powered output for such things). See the picture, almost 7.5kW :-)
Hi experts!! I'm a beginner and working on CC3200 LP along with Energia IDE. I'm working on a simple project where I've an external device which has RS485 o/p and I need to fetch the values in specified addr location in that device to CC3200 LP. My doubts are #1) we have external module that has device ID+parameter Address and we need to transmit the value in LP through UART, here I'm not sure how to use the UART function to specifically target device+address and return/get the same.... #2) what I'm looking/exploring is that in above example (UART code which Andy shared here ) what function specifically reads DeviceID+parameter Addr and returns that string value to my LP My experiments: I've been checking uart.h file and following lines looks close to what I need to do - but not sure... extern void UARTConfigSetExpClk(unsigned long ulBase, unsigned long ulUARTClk, unsigned long ulBaud, unsigned long ulConfig); extern void UARTConfigGetExpClk(unsigned long ulBase, unsigned long ulUARTClk, unsigned long *pulBaud, unsigned long *pulConfig); I'm planning to have my framework Energia sketch might be like calling below functions in specified order 1) UARTIntClear ==> to initialize/clear in LP 2) UARTIntEnable ==> enable UART of my LP 3) UARTConfigSetExpClk ==> to set what I need to read from the external device to my LP 4) UARTConfigGetExpClk ==> to GET what I need to read from the external device to my LP 5) perform step 1 to 4 after 5 sec ==> loop it Am I missing something in above flow?? My Setup I've installed Tera Term in my PC to monitor com port I've got Rs485 to RS232/TTL converter which can be connected to my cc3200 LP UART PIN_02, PIN_01 (RX_1 & TX_1) ... or nay other UART pin which is applicable. my external device which has RS485 o/p ==> Baud rate of 9600, Parity = Even, Device Address = 1, Stop bit = 1, Data type = 32 bit float real, Data to be red from address (Float) 3913, 3909, 3903, 3965, please advice
I am using the Modbus RTU library for Arduino for TIVA TM4c1294ncpdt. Slave(Modbus_Slave Software on PC) is responding to master request but master somekind does not proccess informations that he gets. So I can not regulate LED on master side over potentiometer on slave side. Also master stops sending request to slave after 10 requests sended to slave (when retry_count is set to 5). Problem is: 1) master send request to slave, 2) slave gets request 3) slave process request, 4) slave returns answer to master 5) master gets answer 6) master do not process slave answer After 5 requests (10 actually: PRESET_MULTIPLE_REGISTERS - 5 times and READ_HOLDING_REGISTERS - 5 times), master stops sending request to slave, due to retry_count which is set to 5. If I set retry count to 5000000, it still stops sending requests.