For these secondary devices you have to implement your periodic heart beat check in some device specific rs485 cable way. So take advantage of that and let your systems MCUs implement heart beat handshaking directly though the RS485 communications layer using appropriately designed small packets. If one or the other end fail to see the heartbeat packets come or get acknowledgement of them then know that your cable is either disconnected or has broken wires. For devices where you have to consider the devices at the far end of your cables to be unable to be modified, either hardware or software wise, you have to get clever regarding how you determine if the device is connected. Users now have the ability to monitor their live data and store all the information on the Brainchild itself or on a connected PC. Configuration and data accessibility were a snap: the FieldLogger's user-friendly configurator software was accessible by Ethernet, USB or RS485, and also provided means for online monitoring, downloading of all logged data, rs485 cable and quick exporting to spreadsheets and other formats. No I have not been able to test this using the Windows software.

The device ships with an Ethernet RS-485 communication interface as well as a RS-485 to USB cable, which is said to be able to communicate with a PC using proprietary Windows based software (and driver, I think). The mention of "Ethernet RS-485 communication interface" confused me. Is it necessary to do the ethernet cable splicing as indicated in the above link, or should I simply be able to use the provided USB cable? But I notice that he describes using a (different) RS-485 to USB converter and splicing from the Ethernet cable to the converter, rather than using the converter cable that ships with the charge controller. Note that this Hackster project does something similar with splicing an ethernet cable to a UART breakout module. I am working on a project that involves a Solar Charge Controller. What I want to be able to do is to communicate (or at least read from) the charge controller from a Raspberry Pi. If you have not yet compiled the GETSTART program and you want to do the exercises here, open GETSTART.C in your TextPad editor, click on the Make Tool, and after the compilation is done, enter Mosaic Terminal by clicking on the terminal icon and use the "Send File" menu item to send GETSTART.DLF to the QScreen Controller.

Is it likely that the shipped cable is configured differently or do I simply have no way of knowing that (short of dissecting the cable)? Each device has a communication port with two terminals, which are indicated for the sake of convenience as A and B. In these two terminals the communication cable is connected so that all the devices that take part in the communication are connected in parallel. Because all of the serial I/O routines on the PDQ Board are revectorable, it is very easy to change the serial port in use without modifying any high level code. We will pull the enable pin high to put the MAX485 module in transmitter mode. Electronic data communications between elements will generally fall into two broad categories: single-ended and differential. 5 should work in your situation because of the voltage you will be running (5-10V) and your signal is not high frequency (above 500Mhz) in the first place. The standard C serial I/O routines such as printf(), scanf(), putchar(), and getchar() give you high level access to the serial ports.

The foreword to the standard references The Telecommunications Systems Bulletin TSB-89 which contains application guidelines, including data signaling rate vs. Yes, it would work for that too, but 24 awg cable with plenum grade jacket is the standard. The most common cable type is Cat 5e-UTP (unshielded twisted pair) which may work over shorter distances in less demanding applications with low EMI noise levels. Rs485 is low impedance balanced , so twisting the pair helps with noise immunity as well as reducing the attenuation effect of higher baud rates due to the parallel capacitance of the wires in the cable jacket over the long lengths. So I would not run low level MCU GPIO level signals over the cable wires. The recommended arrangement of the wires is as a connected series of point-to-point (multidropped) nodes, i.e. a line or bus, not a star, ring, or multiply connected network. The recommended arrangement of the wires is as a connected series of point-to-point nodes, a line or bus. RS-485, like RS-422, can be made full-duplex by using four wires.