ChuckM

DVR_Expert_Australia, The GeoVision feature list that you posted here is well-written and very helpful. It is easier to understand than any other documentation I've read about GeoVision software. I forwarded it to my supervisor and manager. Thanks, Chuck

Does anyone know if there are any DVR cards that will allow for "quadruplex" operation? I want a card that allows for simultaneous viewing/recording, playback, and backup, or at least allow simultaneous viewing/recording and backup. I don't want to have to stop recording to run a backup. Thanks

Forgive my ignorance, but I don't know what a "looping switcher" does. This is the definition I found: "Looping switcher: is a type of switcher with looping outputs. These outputs allow the camera to be connected to another device without affecting the usage of the switcher." Is this like using a "splitter" to send the camera signal to both the DVR and a CRT monitor, thereby allowing you to view the image real-time on a CRT while the DVR records at whatever its fps capacity is?

Rory, AVCONSULTING, DVR_Expert, Thanks for all the feedback. The points about being able to upgrade and replace components of a PC system when something breaks have decided it for me. I definitely will recommend a PC-based system. It's the logical choice for us since we have a big PC Support department with many knowledgeable, experienced techs. Another question: Say we go with a GeoVision 480 fps card that allows the frame rate to be adjusted for each camera, and we find it's eating more hard drive space than we like. Can you lower the frame rate for the cameras to the point that it isn't using the full 480 fps, or will the card automatically allocate all of it? It only seems logical that we should be able to use a lower total rate, but I don't want to make that assumption. Thanks

Hello all. It's been a while since I made the original post. The project was on hold for a while due to higher priority tasks, but now I'm back on it . I've been reading through the various forums to learn as much as I can. I have a couple more questions I hope somone can answer. Questions about "stackable" DVR cards: I found a company online that sells a "stackable" 16-channel DVR card.(http://www.dvrsecuritysystems.com/all_new_stackable_120_fps_cards.htm). In the user manual I downloaded, it says the Sentry DVSS4 "can accept up to 32 cameras on frame rate up to 480/240fps depending on model type." 1. Have any of you ever used "Sentry" brand cards? If so, how does the quality compare with GeoVision cards? 2. Have any of you ever built a 32-camera PC-based system with "stacked" cards? If so, how do you "stack" cards and how well did the system work? These cards are rather pricey, and I imagine that two PCs with 16 cameras each would perform better than one PC with 32 cameras anyway, though it would be nice to be able to record 32 cameras on one PC. Opinions? Question about recording resolution: According to the GeoVision GV-800 spec sheet, the "recording resolution" options are: 320 X 240, 640 X 240, 640 X 480, and 640 X 480-SW What's the difference between 640 x 480 and 640 x 480-SW? Question about fps rates: The overall max fps for the GeoVision 800 is 120 fps (NTSC). As I understand it, that is is based on 320 x 240 recording resolution. About how much slower is the fps when recording 640 x 480? I just sent an email to GeoVision to request an answer to this question, but I'd also like to know your actual experiences with the cards. Also, I've read a couple of comments indicating that PC-based systems will eventually be replaced by standalone systems. For example, in the thread "New Geovision GV-250 card for $75 ... is that a good deal??" "squale" wrote: "yeah somebody I know in the business was telling me that the computer systems using DVR cards are becoming less and less popular and standalone systems are really much more popular and will become even more and more popular with time." Do you forsee a time when GeoVision, for example, will stop making DVR cards for PCs? If we put together a PC-based system now, will it be obsolete in two years? Will the manufacturers still offer support? I would prefer the stability of a standalone system, but the fps rates seem woefully inadequate compared to the rates available with the DVR cards, especially considering how much more the standalone systems cost. When are the fps recording rates of standalone systems going to catch up with that of the PC DVR cards? Thanks

AVCONSULTING, DVR Expert, thanks for all the info, suggestions and links. I'll definitely try to find a local distributor. Despite the warnings about using our own PC's, I'm still leaning towards going that way, simply due to the cost of the turn-key units. However, the next step is to show the recommended PC specs to our PC people to get an estimate on how much the PC's would cost to build. Then we can do a cost/benefit comparison with the turn-key systems. Thanks for all the input. I'll post updates on what we do and what happens, and I'll keep checking back here in case anyone has any additional ideas or comments. Thanks again, ChuckM

Larry, Rory, Thanks for replying. I found this forum by doing a search on Google, so I guess you can consider your forum to be "googleized" now. Thanks for mentioning that video playback is only 5 x 6. I just assumed it would be full-screen like the VCR video playback. That's something to add to my notes. Also, I will be sure to pass on to our techs your point about building "server class" PCs. And, yes, I think we're going to use our existing cameras. Again, trying to keep the cost down. Everything in our computer room is already on a large UPS, so the PC's will be protected from power system surges, but what about protecting the PCs from any surges through the coax cables? Is that a concern? I'd hate to fry an $1100 DVR card. Is there any type of surge protect to run the coax cables through? Rory, I really haven't given much consideration to a non-PC based system simply because of the cost. I looked up info about the Kalatel DVR systems you mentioned. Each 16-input DVR would cost between $4000 and $5000. Multiply by 3 (for 48 cameras), and the cost seem considerably higher than for build-it-yourself PC-based system. I suppose I should present that as an option, though. Thanks for your input. Which suppliers have y'all had good experiences with? Any you would avoid? Can either of you answer the question regarding PAL v. NTSC? Thanks, Chuck

First, thank you for creating this forum. So far, it's the only place I've found online for objective advice about DVR systems. It's clean, well-organized and easy to navigate. Although I am not a PC or technical professional, I have been assigned the task of doing the preliminary research for upgrading my company's video security system. I have been browsing the Internet to learn about the basics of DVR cards. (If I read anymore at this point I think my head is going to explode ) I am confident that our PC-Support department can build the required PCs (I'm assuming a Win2K-based system, since that's what we use on almost all of our PCs), so I am at the point of deciding which brand and fps rate DVR card to go with, and which retailer to contact. I have several questions. First, some background: Our video surveillance system for a six-story office building/plant area. The cameras (all B&W) are mostly inside, in the stairwells and elevator areas, but also cover the lobby and parking garage gates. Our current system uses three VCRs, each with a multiplexer. They record "24/7". Each VCR is set to record 18 hours/tape, but we switch-out the tapes every 12 hours. Each multiplexer is maxed-out with 16 cameras, so we currently have a total of 48 cameras (at this location), but we want to add more. We do not use or need audio recording with our system. We keep our VCR tapes for 30 days before re-using them. We seldom have any security problems that require us to go back and view a video tape, but the few times that we've had to it has been very time-consuming to find the right moment on the video tape, and even when/if we do, the recording rate is so slow that the exact moment of interest may not have been recorded. Based on what I've learned so far... To support the current 48 cameras, we'll need at least three PCs, each with a 16-input DVR card. My understanding is that a 16-input 30-fps card would give us only about 1.8 fps/camera - if all the cameras are actually recording at the same time. I assume we will use the motion-detection feature of the cards so we aren't constantly recording from each camera. Still, since the whole point of this project is to UPGRADE (to something that will last for many years), I'm thinking we should get at least 60-fps cards, preferably a 120-fps cards. Any thoughts/comments on this? Regarding brands of card, I've found the following (each claiming to be the "most advanced", of course): GeoVision, TAI Labs, G-Max (sold by skywaysecurity), Bolide, and AVerMedia. Also, there is a company called dvrcards.com that sells its own "professional" brand, which they claim is better than the "economy" GeoVision or TAI Labs cards they sell. My main concerns are hardware compatibility, ease-of-use, and reliability. I've read good comments in this forum about GeoVision cards. I'd appreciate any input/comments on other brands. I also have a question about video compression formats. The most common combination seems to be "wavelet" or Mpeg-4, but some brands offer JPEG. Any comments on this? Also, the software for the various brands of cards all seem to offer the same features. Any comments on which company's software is the most reliable and user-friendly? Also, which companies provide the best documentation and offer good support for their products? Question about PAL v. NTSC (forgive my complete ignorance on this one): I've read that the fps is affected by whether you are recording in NTSC or PAL. What determines which type of signal (NTSC or PAL) a system records in? Is it based on the type of video display monitors and/or cameras being used? Since I'm in the U.S., can I assume that our system records in NTSC? Or, is there some setting in the DVR card software that allows you to choose which signal you want to use? Which retail suppliers have you had good experiences with? Which would you steer clear of? Finally, do you know if there are any suppliers that will allow a potential customer to "demo" a card for a short time to see how well the card performs? All suggestions and comments welcome. Thanks, Chuck