Can I control ... over IP?
Posted: Sun Apr 28, 2013 9:09 pm
IP Control of devices is becoming more widespread, however for the custom install market there are several considerations as to whether you would want to control something over IP, even if it is possible. In our opinion, in the not too distant future, pretty much everything will be IP controllable one way or another, however in the here & now you should ask yourself these questions before automatically assuming that IP control is the preferred approach:
1. Is the IP control protocol / command list published by the manufacturer?
If the commands have been grabbed using wireshark / by other non-authorized means, you need to consider whether to make your system rely on those commands. Automatic firmware updates etc may change things in the future, causing your system to suddenly stop working. Only with the documentation & approval of the manufacturer should you really proceed.
2. Can the device accept multiple client connections at the same time?
Vital if designing a system which may (and not necessarily on day 1) have multiple controllers
3. Does IP control remain available when the device goes to standby mode?
Often the Ethernet port of a device is turned off when the device goes to standby...at which point unless WOL works on the device (which it often doesn't), you will be unable to turn it back on. This is particularly a problem with TVs. Some devices, eg amplifiers have a 'network standby' option which keeps the network port open.
4. Is the list of IP commands complete?
Often IP control is built in to a unit to only perform certain operations. You need to consider whether the command list is complete for your needs.
4. Is IP control implementation robust for the device?
We know of several devices whose IP implementation is not 100% reliable, working for hours or days at a time, and then locking up, requiring a hardware reset of the device. Firmware updates may resolve, but for a given device, RS232 control for example is usually always more robust than IP control, as it does not rely on any external factors (eg the network infrastructure)
Now, there are many devices that fit all the criteria above, including HDMI matrices, amplifiers etc. For those that do not satisfy all the criteria above though, our advice is to consider the control method carefully.
1. Is the IP control protocol / command list published by the manufacturer?
If the commands have been grabbed using wireshark / by other non-authorized means, you need to consider whether to make your system rely on those commands. Automatic firmware updates etc may change things in the future, causing your system to suddenly stop working. Only with the documentation & approval of the manufacturer should you really proceed.
2. Can the device accept multiple client connections at the same time?
Vital if designing a system which may (and not necessarily on day 1) have multiple controllers
3. Does IP control remain available when the device goes to standby mode?
Often the Ethernet port of a device is turned off when the device goes to standby...at which point unless WOL works on the device (which it often doesn't), you will be unable to turn it back on. This is particularly a problem with TVs. Some devices, eg amplifiers have a 'network standby' option which keeps the network port open.
4. Is the list of IP commands complete?
Often IP control is built in to a unit to only perform certain operations. You need to consider whether the command list is complete for your needs.
4. Is IP control implementation robust for the device?
We know of several devices whose IP implementation is not 100% reliable, working for hours or days at a time, and then locking up, requiring a hardware reset of the device. Firmware updates may resolve, but for a given device, RS232 control for example is usually always more robust than IP control, as it does not rely on any external factors (eg the network infrastructure)
Now, there are many devices that fit all the criteria above, including HDMI matrices, amplifiers etc. For those that do not satisfy all the criteria above though, our advice is to consider the control method carefully.