Here's the initial proposed hardware - RS232. However, I just discovered that they also have this - Ethernet. So, now we have a choice.
- RS-232/USB radio modem: Allows us to put serial devices anywhere. Options include display board and/or time-slip printer.
- Ethernet radio modem: Allows us to put an Announcer Client laptop anywhere. Options are unlimited!!
The difference in price between the serial and the ethernet options is about $100 for each modem. However, if we go the ethernet option, we also will probably want another laptop. It also will increase our power requirements at the top of the hill.
USB Background Information
USB has two types of devices: Those that supply drivers (a host, such as a PC); and those that require a driver (a client, such as a MaxStream? USB RF Modem). When a USB client is plugged into a host, the host prompts the device for a driver. Once a driver is located, the host loads the driver on the first use of the USB client; then supplies the installed driver on all subsequent uses.
A USB client should not be plugged into another client. If another USB client (such as a USB video camera) is plugged into a MaxStream USB RF modem (also a client), the devices will not communicate. It would be incorrect to attach a USB modem to a host on one end and attach a USB modem to a USB client at the other end. Virtually all USB peripherals (video cameras, PDA cradles, printers, etc.) are USB clients.
Some client devices can act as a host. This is known as �USB on-the-go�. An appropriate USB on-the-go enabled device (such as a PDA with USB on-the-go support) may connect to and utilize a MaxStream USB RF Modem. Contact MaxStream for information about device drivers.
Based on this, will we be able to utilize a USB modem for our application?? It appears as if they are saying the modem
must be attached to a USB host and the devices we were going to put at the top of the hill are USB clients.
The RS-232 modem does not have this drawback. It can connect to either a DTE (host) or a DCE (client) using a NULL modem connection. This means that our multiple devices at the top of the hill idea won't work.
Budget
Budget Option A (RS232):
| Item |
Price |
Qty |
Total |
| Radio Modems |
$250 |
2 |
$500 |
| Yagi antenna |
??? |
2 |
??? |
| RJ cables (modem to yagi, 25 ft?) |
??? |
2 |
|
| RS232 cables (modem to host/client, 3 ft?) |
??? |
2 |
|
| NULL modem adapter |
??? |
1 |
|
| Battery for top (bottom runs off generator) |
??? |
1 |
|
| Time-slip printer |
??? |
1 |
|
Budget Option B (USB):
| Item |
Price |
Qty |
Total |
| Radio Modems |
$250 |
2 |
$500 |
| Yagi antenna |
??? |
2 |
??? |
| RJ cables (modem to yagi, 25 ft?) |
??? |
2 |
|
| USB cables (modem to host/client, 3 ft?) |
??? |
2 |
|
| Battery for top (bottom runs off PC) |
??? |
1 |
|
| Time-slip printer |
??? |
1 |
|
Radio at base can be powered via USB
Budget Option C:
| Item |
Price |
Qty |
Total |
| Radio Modems |
$350 |
2 |
$700 |
| Yagi antenna |
??? |
2 |
??? |
| RJ cables (modem to yagi, 25 ft?) |
??? |
2 |
|
| Battery for top (bottom runs off generator) |
??? |
1 |
|
| Time-slip printer |
??? |
1 |
|
A closer examination of the ethernet solution mentioned above resulted in bad news. It is not what I thought it would be. It only provides a single RS232 stream.
New plan
They also have this. This is the answer! We once again have the possibility of Ethernet at the top of the hill!!!
Welcome
