Structural analysis of an exhibition hall requires temperature measurement to complement the strain, acceleration and inclination measurements. Temperature is measured on multiple points across the roof to help distinguish between mechanical and thermal loads. Low cost temperature sensors (AD592) were used to measure the temperature and MonoDAQ-U-X was used to acquire the analog signal and bring it into a Dewesoft application.
Since the measurement points were far away from the central PC running Dewesoft, the U-X needed to be displaced and conected over a UDP link. This is achieved by attaching an industrial RaspberryPi computer running Linux to the configuration as explained in the following sections.
The components of the remote system:
- AD592 temperature sensors (4 pcs.)
- RevPi Core3 (industrial implementation of RaspberryPi) running Linux
- 24 V power supply
- Circuit breaker
- Electric cabinet with 230 V power source
In this configuration the sample rate of the MonoDAQ-U-X is limited to 1 Hz which is ideal for temperature measurement. Contact firstname.lastname@example.org if there is a need for higher sample rates over UDP.
The picture below shows the components of the system and a basic connection diagram for UDP access to the MonoDAQ-U-X from a host Windows PC running DEWESoft.
Software running on the remote system was configured in-house and no additional actions were neccessary by the user. After about 30 seconds from the power up of the remote system, the software is ready for the UDP connection to be established from the cetnral PC. To explain the background, a real-time version of Linux is running on the RevPi, which also runs the Isotel IDM gateway software. IDM interfaces with MonoDAQ-U-X and acts as a bridge between the device and Dewesoft application that is running on a central PC and is only connected to the RevPi and U-X over the UDP network.
To enable the UDP connection to the remote MonoDAQ-U-X, the following steps need to be followed:
- Connect the network cable from the remote system to the host PC
- Set the static IP address of the ethernet port on the host PC to: 192.168.150.1
- Place the monodaq-u_udp_remotes.dat text file in the DEWESoft/System/X3 folder. The file should contain IP addresses of the remote systems to connect to. Each IP should include the port number 8100. For this system only one IP address needs to be entered (192.168.150.2:8100, which is the static IP address of the RevPi Core3 eth0 port)
- Open DEWESoft (or restart it if it was open during the changes to the .dat file). Make sure the MonoDAQ-U plugin is enabled. You should see the screen below. Make sure to tick the “Asynchronous” tick box. This will make the MonoDAQ-U-X device work with the E-series devices. The sample rate of the MonoDAQ-U channels will be automatically reduced to 1 Hz.
If the device does not yet appear in the list on the right half of the screen, click OK, enter the MonoDAQ-U plugin screen in Channel Setup and wait a few seconds.
- If the connection is successful, you should see the channels from the MonoDAQ-U-X device in the plugin setup screen:
- The MonoDAQ-U-X was shipped with a TEDS chip inserted into pins D9 and D10. The chip holds the device configuration for this temperature measurement application. The name of the configuration is visible in the first row of the ID column and should read “a4xAD592”. The configuration only includes the setup of the channels, but not the channel names, offset, scale and unit. A Dewesoft setup file was provided that includes the correct values. The offset should be -273.15, the scale should be 4.00 and the unit should be degC for all four temperature channels. The figure below shows the configuration after the setup UX-4xTempAD592.dxs is loaded:
This completes the UDP connection and the MonoDAQ-U-X temperature measurement channel setup.
Wiring of the AD592 temperature measurement sensors to the MonoDAQ-U-X
The wiring of four sensors is shown below. 250R precision resistors were shipped with the system while the sensors were supplied by the customer.
Remote operation of the MonoDAQ-U-X over a UDP link makes it completely configurable from within Dewesoft as it would have been connected directly to the central PC over USB. The maximum sample rate of 1 Hz is ideal for the temperature measurement or other long-term monitoring parameters. Since the acquisition is asynchronous, this configuration can be connected together with the chain of MonoDAQ-E series devices (EtherCAT). Multiple remote systems can be connected to Dewesoft over the UDP network.
Contact email@example.com for any further questions regarding this system.