Posts Tagged “mtxtunnel”

This weekend I brought a little toy home to mess around with. I wanted to try it out for a long time. It could be useful in some applications in the m2m world which is becoming more and more present in our lives, although many do not realize it.

This little device is a mini camera module with VGA resolution from Comedia which in turn is based on a CMOS sensor from Onmivision (the world’s largest manufacturer of these types of devices, so much so that nearly all of us have one of their sensors in our mobile phones). So far it’s nothing special. The peculiar thing about this mini camera is that as well as its low cost, you can directly control a uart through a serial port with a very basic protocol suitable for everyone.

The latter obviously enormously helps you to be able to control the camera and get a picture of what is happening in the world from any device with a serial port. In my case, I am particularly interested in the possible integration with MTX65i modems, especially with MTXTunnel software. I am assessing how much time it would take to integrate the possibility of “taking a snapshot” from the MTXTunnel or even from the  MTXTunnelGPS.

The camera I’ve been testing is particularly the model I had at hand, the C328R. The following is the block diagram of the camera:

camara-serie-diagrama

It’s a very small camera (only 2cm x 2.8cm), with VGA resolution, with low power consumption (60mA) and as I said before with the serial control peculiarity (UART). Note that this camera has serial ports but doesn’t have an RS232, this means that RX and TX output level is 0-3.3V so we can’t directly connect to a PC’s serial port or a MTX GPRS modem. Fortunately, there is also a small evaluation board called C328-EV232 that allows this and adapts RS232 levels. This is what I am testing.

Here is a picture of the evaluation board next to an MTX65i so that you can see how big it is:

camara-uart

And here is another with the C328 module mounted on its mini evaluation board:

camara-rs232

Together with the mini evaluation board you get a CD-Rom with the datasheet from the camera and from the evaluation board itself, a rapid use test program (which does not work with Win7 but works with WinXP, it doesn’t really matter) and most importantly, the complete manual of the camera’s protocol which tells you how to configure the camera (resolution, compression etc.) and how to get an image from the serial port. It’s fairly informative which means that it is easy to do the first tests. This is a picture of the software test:

camara-serie-ejemplo

Basically, in addition to trying out the test program that comes in the CD-Rom, I have done some tests sending serial frames to the camera from a VB6 program. I followed the protocol and example in the manual and it responds very well. From what I gather, it doesn’t take much to generate the necessary JAVA code to take a snapshot from an MTX terminal.

It’s obvious that you can’t send video streaming from a GPRS terminal as the bandwidth does not allow it. But yes, it could be interesting to occasionally send some snapshots (we’re talking about very few KB, according to the settings less than 10KB per image) as this doesn’t cause any problems for GPRS transmission. For example, if we designed an alarm system using an MTX65i GPRS terminal, it could be interesting as we could send an image as well as sending an alarm. Or it could be interesting for a fleet management system (based on the MTX65 + G) that as well as GPS positioning via GPRS, it allows you to physically visualize the load at any given moment (for example when opening a trailer’s doors).

To conclude, if you sacrifice very little time and money, this little camera allows you to send photographs to any device that has a single serial port free. Small details like this are what differentiate devices that we can design over others, in a world which is becoming more and more competitive and in which there is more and more of everything.

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A month ago I posted about Coronis telemetry devices. We saw that they have IP68 devices that can read remotely via radio frequency (on the 868MHz band), digital inputs, 4-20mA or 0-10V analog inputs and temperatures/meters for water/gas/electricity. A lot longer ago, I also posted a video about the MTX-Industrial modem which you can optionally order with a Zigbee, Bluetooth or Coronis communications card.

So taking advantage of all of this, I have included an additional, interesting feature to the new MTXTunnelv5.6 (which is an application that as many of you know can be requested in any programmable MTX terminal). I have added a GPRS-Coronis communications gateway.

What do you use a GPRS-Coronis gateway for?

Let’s take an example. Imagine that you have a large area (several kilometres squared) with several hundred water meters that you want to read every day. A water meter quite simply generates a pulse (dry contact) for every X litres of water that flows through it. Therefore we will physically connect a Waveflow to each water meter. The purpose of each Waveflow is to count pulses that are generated by the water meter that it’s associated with i.e. said simply each Waveflow will know about the water that has flown through the meter at all times.

Obviously to read meters we could go to wherever they are every day with a PC + Waveport, but it would probably be better to take a reading from your own office as it’s warm in winter and cool in summer and you also avoid travel costs.  This is where you will find the new GPRS-Coronis gateway useful. Let’s look at this explanatory graph:

concentrador-gprs-coronis-w

As you can see the communications hub is an MTX-Industrial (with optional internal Wavecard) + MTXTunnelv5.6.

Very good and how do I read the data from meters from my office?

Among all of its features, you can use Telnet with MTXTunnel. When connecting to MTXTunnel from your office via Telnet you can send AT commands (e.g. switch a relay remotely), read a digital or analog input, read GSM coverage etc. So I’ve added two simple AT commands called AT^MTXTUNNEL=SETWAVENIS,tramawavenis and AT^MTXTUNNEL=GETWAVENIS. With these two AT commands you can directly send Wavenis frames to the MTX-Industrial’s internal Wavecard via Telnet. This will allow you to read and connect to Waveflow meters.

Yes the MTXTunnelv5.6′s new feature doesn’t get rid of the fact that you have to take a look at the Wavenis protocol manual, but it can save a lot of work. For example if I want to communicate with a remote Waveflow I only have to do something like this:

telnet-wavenis

This means that with “AT^MTXTUNNEL=SETWAVENIS”, we send the “frame in question” to a Waveflow and with “AT^MTXTUNNEL=GETWAVENIS” we get the response received from Waveflow. It’s as simple as that. The same goes for being used with any Coronis device, i.e. to monitor temperatures (wavetherm), distributed digital inputs/outputs etc. You have more information in the manual and of course if you have any doubts you can tell me on the blog or via email jose@blogelectronica / jgallego@matrix.es

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This is a brief post just to let you know that the MTXTunnelv5.4 is already available. This new version of MTXTunnel is totally compatible with previous versions. Basically, it has two new features in addition to the many that it already has:

On one hand it allows telemetries to be sent via GPRS socket or HTTP (i.e. the state of digital and analog inputs) when there is a change in digital inputs or an analog value is over/under the limit. In previous versions, telemetries could be sent periodically every X amount of time, now they are sent when something changes. It works in the following way: once it detects a “trigger condition”, the states of all digital and analog inputs are read and sent to a remote server.

alarmas-gprs

On the other hand, you can configure MTXTunnelv5.4 as a GPRS ModBus-TCP to ModBus-RTU gateway just by simply adding the following parameter to the configuration file:  ”MTX_gatewayModBus: on”

modbus-tcp-modbus-rtu

As always the User Manual includes working examples. Specific examples with these new characteristics are numbers 2.13 and 2.14 in pages 185 and 187 respectively.

Regards.

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