Ren-W Questions/Answers

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  • Can a Ren-W be connected directly to the computer?
  • Yes, but early versions of the Ren-W board priot to 20100622 may need the RS485 patch (see troubleshooting page) for it to work reliably unless the Ren-W board is version 20100622 or later; the later revision does not require the patch. The patch uses only the ground and -485 signals. However, the board in its current state works fine with passive RS232 - RS485 adapters such as the Sintech 9309, which is available for about $8 from www.dealextreme.com. I've used this off my PC's RS-232 port and connected it directly to the Ren-W without any problems whatsoever. Bottom line: the best way to transmit directly from the computer is to use the XBee USB Explorer instead of a Ren-W. The Explorer doubles as the programmer board, but it's a fantastic transmitter, and appears to your computer just like a normal COM port, so configuring Vixen to use it is a snap. Then you can put all your Ren-Ws out in the field.


  • Can the Ren-W be used with a USB RS-232 to RS-485 converter?
  • Yes. See above.


  • Will RS-232 work with the Ren-W?
  • Yes, as long as the board has been modified as per the RS485 patch outlined on the Ren-W troubleshooting page of the Wiki (pre-20100622 boards only). In addition, you'll want to connect RS232 ground (pin 5) to the Ren-W's J1 pin 1 and RS232 pin 3 to the Ren-W's J1 pin 4.


  • Are the SMA and Rev-6 versions of the Ren-W interchangeable?
  • Not directly. You'll find that using the Rev-6 board with an SS controller requires that JP2 on the SS controller be open and not shunted. (JP2 is the termination resistor on the SS board).


  • Do I have to use a special serial port setting with the Ren-W?
  • Generally, yes. The best setting to use is 57600 baud, 8 data bits, 2 stop bits and Mark parity. This should be configured in both your Vixen plugin AND in the XBee radios themselves. The Renard firmware should also be set to 57600 baud so that the PICs are in sync, too. Note that 57600, 8 data bits, 1 stop bit and NO parity works generally works fine, although you may experience a few data packet dropouts when there are more than 57 channels connected to the same Ren-W board, such as with a Ren64. When daisy-chaining one controller to the next via Ren-Ws, the XBee radios in the daisy-chained Ren-W/controllers must be set to 57600, 8 bits, NO parity and 1 stop bit.


  • Can the Ren-W be powered independently instead of powered by the SS board?
  • Yes. Connect +5vdv to either pin of the JP3 header and ground (-) to either pin of the JP4 header. Do not use a power supply that provides more than +5vdc and never connect JP3 to JP4! (Note: the Ren-W's voltage regulator should not become hot during normal use. Ren-W has been tested with a 12vdc supply and the regulator gets quite warm when powered this way. If you must power the Ren-W with 12vdc, consider attaching a heat sink to the back of the U1 voltage regulator.)


  • What kind of current draw does a Ren-W have?
  • More current is used when an XBee module is transmitting than receiving. The higher-powered XBee Pro module requires upwards of 290ma while the standard XBee module requires only about 50ma. The 3.3vdc voltage regulator on the Ren-W is rated up to 500ma. Because the Ren-W draws its +5v power directly from the Renard SS controller, Ren-W users who experience inconsistent or erratic transmission performance may consider replacing the SS controller’s LF50CV ½-amp voltage regulator (Mouser # 511-LF50CV) with an LF50CP instead ( # 511-LF50CP), which has a full 1A capacity.


  • Does cat5 cable length matter when connecting a Ren-W to an SS controller?
  • Both RS-232 and RS-485 are pretty robust and with RS-485, long cable lengths (up to 4000’) are certainly possible. We’ve tested RS-232 with 100’ cable without a problem but as the basic concept of Ren-W was to eliminate cables, keep them as short as possible anyway.


  • Can I mix Global Broadcast mode with PTP mode?
  • Theoretically yes, if you’re very clever with using combinations of the XBee’s PAN ID and addressing configurations and don’t mind experimenting to see what works best for you. However, start_address firmware in a global broadcast most is most likely going to give you every bit of the flexibility you need, making PTP unnecessary.


  • Can I mix SS8, SS16 and SS24 boards in the same Ren-W network?
  • Yes. In PTP mode, they will function just as if they were connected via cat5 cable (use 57600, 8,N,1 settings). In global broadcast mode where each Ren-W receives the same commands instead of only those passed on from the previous controller, use start_address firmware to tell the controllers which channels they should react to. Re-read the “Renard basics and how they relate to Ren-W” section on the first page of the Ren-W Wiki.


  • Can I mix hardwired SS controllers with Ren-W wireless controllers?
  • Yes, Ren-W was designed to be an easy add-on to an existing wired system in either or both global broadcast, PTP or alternate PTP broadcast modes.


  • Can I use a Ren-W with my Ren-C/595 or Ren-C/Grinch controllers?
  • Yes. It works very well when the RS-OUT of the Ren-C is plugged into the Ren-W's input for transmitting the signal out to the network. However, when the Ren-W is to control the Ren-C/595 or Grinch, it is necessary to also use a snap choke core balun on the cat5 cable going into the Ren-C's RS-IN jack (Radio Shack part# 273-0069). The balun eliminates EMI/RFI interference generated in the cat5 cable that's caused by the XBee radio module. Without the balun, the Ren-C will likely encounter framing errors and will not communicate with the Ren-W. Power for the Ren-W can be tapped from the 595/Grinch +5v header pins, from the Ren-C’s vcc header pin immediately to the left of the 2N3904 transistor (Q1) or from the Ren-C’s vcc header pin of the JP6 PGM row (2nd pin from the top). Note that the ZC signal must be supplied to the Ren-C directly and cannot be passed along wirelessly by the Ren-W. The Ren-C’s RS-485 RS-OUT serial signal is approximately 4.52vdc, which is still within the acceptable range that Ren-W can accommodate.


  • Do I always need two XBee modules on a repeater board?
  • Yes and no – it depends on whether the Ren-W is serving as a normal repeater or whether you want it to be an E-mode repeater. The normal repeater board uses two XBee modules, one for receiving and the other for transmitting. The E-mode repeater uses only one XBee module which performs both receiving and transmitting functions. Other than the obvious price difference between the two types of repeater boards because of the added XBee module, it’s important to understand that there may also be a performance difference because a single XBee module can’t perform receiving and transmitting simultaneously. It’s important to note that the design of the Ren-W allows switching from E-mode to normal mode by simply disconnecting the jumper shunt on JP5 and of course, adding and configuring the second XBee module. So one can always start with the E-mode repeater and if a performance lag is encountered, you can always switch to normal mode without having to take out the soldering iron.


  • Can I use “global broadcast” mode yet have each Renard controller respond to its own range of Vixen channels?
  • Yes, and this is the best and most flexible way to use Ren-W in your display. You will need to use the Renard Start Address firmware to set the start address for your controller's first PIC. Be sure to read the Renard Start Address Configuration Guide for using this special firmware: Renard Start Address Configuration guide. Another way to "skin the cat" would be to think a little creatively. For example, if you used three 24-channel controllers and set up each of their Ren-W receivers so that all three received the same "broadcast" signal, you could connect lights to only channels 1-8 of the first controller (leaving channels 9-24 unused), channels 9-16 of the second controller and 17-24 of the third controller to simulate "broadcast addressing."


  • Can the Ren-W work with other Renard controllers such as the Renard 16, Renard 24 or Renard 64?
  • Yes, but some versions of Renard controllers may have different design versions and the RJ45 serial pin outs as well as the serial signal may vary from the Renard SS board’s design. The Ren-W was originally designed to be a plug-in option for WayneJ's Renard SS controllers but it has been successfully tested with wjohn's Ren64 (v. XC5), budude's Ren48LSD, fkostyun's Ren24 version 3.0 and 3.3 (thanks to DIYC members penfold and kychristmas!) and the Ren24LV, and the Simple Renard 24 and Simple Renard 32. If the RJ45 pinouts are the same as the Renard standard, it should work. However, if the pinouts are different from the Renard standard, you just have to make your own custom cat5 connection cables to connect the Ren-W to the Renard board instead of using the standard, straight-through cat5 cabling scheme. It is also possible that the use of the choke core balun (as for the Ren-C adapter) may be required to help reduce line noise.


  • Will the Ren-W work with DMX?
  • No, because DMX requires a higher throughput than the XBee’s maximum. An XBee is limited to 115,200 and was designed to accommodate streaming data only up to 80kbps. DMX’s communication need is normally higher than that, in the neighborhood of 250kbps. It has been tested with RPM's USB DMX dongle and was proven not to work, but you could certainly give it a go – the Ren-W simply transfers a serial signal from one place to another. You’ll obviously have to consider the connector pin outs used for DMX and you may end up creating your own connection cables to/from the Ren-W to/from your DMX setup, but a completed pair of Ren-W boards are relatively inexpensive to make so the cost of experimentation isn’t very great.


  • Can a Ren-W be used with other light controllers or other devices to create a wireless connection?
  • Maybe. Remember, Ren-W is essentially a wireless serial connection which means that theoretically, it could connect most any serial devices because it’s essentially transparent to the two devices involved – it merely inputs a serial data packet on the transmitting Ren-W’s J1 connector, translates it into a TTL data stream and transmits it to another Ren-W where the data stream is recombined into the serial data packet and output via the receiving Ren-W’s J2 connector. Because it’s a serial device, remember that the serial communication parameters (8 data bits, no parity, no stop in the case of the Renard controllers) can be changed to match a different packet structure such as 7 data bits, even parity, an 1 stop and that such configuration is done inside the XBee modules using the XCTU software. Obviously the transmitting and receiving units must be configured with the same communication parameters so that the serial data at the receiving Ren-W’s output port J2 is in the same format as it was originally when it went into the transmitting Ren-W. Another consideration is that an XBee’s maximum transmission speed is 115,200 bps but is really rated at only 80kbps in continuous, streaming data situations which may or may not be adequate in every case.


  • Will the super-powered 900mhz XBee radio modules work for even greater range?
  • Maybe. Some radios in the XBee line supposedly provide a line-of-sight range of up to 12 miles, but they may not have the same speed throughput capability that you may need and their electrical power requirements may be greater than are designed into the Ren-W board. The concept still is sound, but they may not be a drop-in replacement for the current Ren-W design. However, Ren-W has been tested to easily provide 1000' range when external Wi-Fi antennas are used (using the XBee Pro with SMA connector) so it's a bit hard to understand why you'd need more distance than that. However, the 900mhz radio does not have the same baud rate options as the normal radio, so using it may provide mixed results.


  • Is a Programmer Board a necessity or can I get by without one?
  • It's not terribly difficult to program an XBee using the Ren-W board and information about doing that is included in the configuration section of the Ren-W wiki pages. However, it is a little tricky to accomplish consistently and the programmer board is well worth the purchase and provides for duplex communication with the XBee radio, as well as a way to test modules, test communication, test settings, etc. before putting the units in the field. It can also be used as the originator transmitting module and Vixen can easily be configured to use it. So yes, you can 'get by' but like having a Pic programmer if you use Renard, having an XBee programmer can be just as beneficial. An inexpensive Ren-W explorer solution is to rig-up a special cable that connects RS232 pin 3 to pin 4 of the Ren-W's J1 jack and RS232 pin 2 to pin 4 of the Ren-W's J2 jack, with RS232 pin 5 (ground) connected to the Ren-W's pin 1. Then put the XBee radio in the TX (left) side of the board and place a jumper on JP5. This creates a duplex communication setup with your computer and you can use the XCTU software as you would normally, or even Windows HyperTerminal to program the XBee radio's settings. It's not nearly as efficient or quick as using the XBee USB Explorer board, but it can work if you're patient and want to save the $25 cost of the USB Explorer. A handy solution is to construct your own Ren-W Explorer board such as this one which makes all the proper connections as outlined above. It can also be used to easily connect your RS232 cable to a Ren-W transmitter at the PC:
Renw explorer.jpg


  • Will a version of Ren-W be available for parallel port controllers?
  • No, there are no plans to create a parallel port version. Parallel port-based technology has rapidly lost popularity over the past few years and many computer manufacturers no longer even include parallel ports on their products. However, you could certainly try using a parallel-to-serial converter at the computer end, feed the resulting serial signal into J1 of the transmitting Ren-W and at the receiving Ren-W’s J2 jack, use a serial-to-parallel converter to convert it back into the parallel signal you need. Whether this will actually work is unknown; in theory it sounds like it might work but in actual practice, it may not.


  • What kind of wireless range can I expect to get?
  • Even though the XBee radio’s specifications indicate much longer distances, in actual practice, a regular XBee module should provide roughly 50-75 foot range while the XBee Pro module can generally work up to 300 yards or greater, depending on the kind of antennas used on the units and where the antennas are located (higher is better). The Pro version of the radio has both a more powerful transmitting capability and a much greater receiving sensitivity. Even greater distances are possible, but signal reliability is a major issue when the radios are operating at 57,600 baud, the basic speed that is recommended for Renard SS controllers. Note that you should also expect to experience occasional light flickering or even miscued lights that are caused by data dropouts, a common occurrence with high speed wireless serial connections that use streaming data without a hardware or software flow control mechanism. If the SMA version of the XBee Pro module is used with an efficient external antenna, one might experience incredible range. In cursory testing, a 14" external SMA antenna with 6db gain easily provided about 1000' of working distance, but results may vary depending on your situation. However, extreme distances such as miles have not been tested as they seem outside the scope of intended use.


  • Will this interact with my home wi-fi network?
  • Possibly. Wi-fi generally operates in the 2.4ghz radio spectrum, same as the XBee radio. It has been proven that when a wi-fi device is in close proximity to an XBee radio, the XBee's reception can easily be hampered by the power of the wi-fi device's transmitter. The symptom is that the Ren-W starts acting randomly or may seem to lock up or be unresponsive. Usually removing the wi-fi device from the immediate area should solve the problem. Xbee radios can use many different Wi-Ri channels, and you may have to experiment with different settings if your experience interference. The Troubleshooting section of the Ren-W Wiki includes a notation on this very issue.


  • I’m concerned about dropped data. How might it affect my light show?
  • In testing, the range of dropped bytes was in the neighborhood of .014 to .044%, equivalent to between 14 - 44 bytes out of every hundred thousand bytes transmitted. A typical song of 2½ minutes’ duration with moderate lighting commands for an SS24 controller might result in about 60K of Renard control data using 50ms timing in Vixen sequencing software. Applying the percentage formula, that could result in 8 to 26 dropped bytes; at one byte per cell, that’s equivalent to 8 to 26 cells over the course of the entire song. It could appear as a light that’s one cell (50ms) late in turning on or off, or if the byte represents a cell that’s in the middle of a long ramp up or down (4 or 5 seconds), one or two very slight flickers. In most cases, viewers probably wouldn’t even notice them.


  • Can you make it so no bytes are dropped at all?
  • No, as this would require the use of flow control which, in a fast-paced streaming protocol that is often synchronized to a music track, tends to slow things down and data may eventually become out of sync with the music. The current Renard protocol assumes a direct wired connection, but it includes a space bit which is intended to help solve possible data flow issues and timing. There is no functionality built into the Renard’s PIC code for either software or hardware flow. Something you can try is to change Vixen’s Renard plug-in setting to use 2 stop bits instead of the normal one stop bit and see if that makes a difference for you. Of course, the stronger the radio signal is, the more likely fewer dropped bytes. Consider upgrading to the XBee Pro module if using the standard one, or possibly an SMA version and an external antenna. Wireless communication is never as secure as wired communication.


  • Can I mount the Ren-W inside one of my waterproof broadband-type controller boxes?
  • Yes, but keep the XBee’s antenna away from any transformers, A/C power and any triacs for best performance. Also, don't put it inside a metal case -- that won't work at all. Also understand that the more impediments you place between the transmitting and receiving antennas the less workable distance you’ll get. Lastly, if you decide to mount the Ren-W on the inside top cover of your broadband case, consider using the side-entry RJ-45 jacks and a little longer cat5 cable instead of the top-entry version and a shorter cable. This will reduce stress on the cat5 connectors on both the Ren-W and the controller. There are antenna extension cables available but using them is generally not very successful as the cable soaks up all the transmitting energy. For Xbee to be successful, the distance between the antenna and the radio should be very short.


  • I'm having trouble with channels 57-64 on my Ren64 with the Ren-W. What's going on?
  • There is a timing incompatibility between the Ren-W's XBee module and the Ren64 when both are running at 57,600 baud, 8 data bits, 1 stop bit and no parity. Try using MARK parity and 2 stop bits instead. Update: a suggested combination firmware/hardware solution to this problem is available on the Ren-W Troubleshooting page. Additional viable solutions include dropping down to 38,400 baud which completely eliminates the problem. Alternately, you can certainly use the Ren64 as-is without plugging anything into channels 57-64. However, the best (and easy) solutions are found on the troubleshooting page and the change to MARK parity and 2 stop bits is the simplest. Of course, you must set both the Vixen plug-in and the XBee radio to communicate at the same settings.


  • Can I modify the design on my own and improve it?
  • Absolutely -- that’s in the truest spirit of DIYC! Remember also that you must then provide your design to other DIYC members without charge so that they may benefit from it, too. As a practical design suggestion, you’ll notice that the solder pads for XBee headers H1-H4 are elongated. The larger pads provide for a better home-etched board because otherwise, the tiny 2mm solder pads may be too small for enough solder to hold the headers to the board.


  • Where can I get more information about XBee radios?
  • Contact www.digi.com, makers of the XBee line. Their technical support staff is responsive, knowledgeable and courteous. There are also links to user forums on the digi web site and the discussions there are quite timely and helpful.


Additional Ren-W Links