Installing a DAS: possible challenges and efficient solutions.
A distributed antenna system (DAS) is a network of antennas that are used to provide wireless services in a large area. They are often used in commercial buildings, stadiums, and other large venues to ensure that there is reliable cellular coverage. There are several types of DAS systems, and after you choose the type that best suits your building’s needs, the time comes for installation. However, as many found out the hard way, there are several issues that can arise before, during and even after installing the DAS system. Fortunately, there are just as many, if not more, solutions for every issue and there is always a way to optimize your DAS system.
As always, prevention is the best cure, so being informed about potential challenges will make it much easier to tackle them easily and efficiently. Read on to learn all about these possible issues and what to do if/when they arise.
What kinds of issues can you expect during installation?
When installing a DAS system, it is important to consider the various possible installation issues that may arise. Broadly, these can include signal interference from nearby buildings or other sources, the need for additional antennas or amplifiers, and the need for special cabling or power sources. Additionally, it is important to ensure that the system is properly configured and tested before it goes into operation. So best practice suggests that you go over every detail before the installation begins, to weed out any potential issues for the get-go. And since DAS communication errors can occur on both the networking side and the serial communication side, it is best to be thorough.
Networking Issues
Connecting a device to the Distributed Antenna System (DAS) requires multiple parameters to be configured correctly. It is essential that these details are accurate, as even a slight error in an IP address can force the device off network.
Common misconfiguration issues include:
- Overlapping, duplicated or mistyped IP addresses
- Incorrect programming for the IPS or subnet mask gateways
- Network mask misconfiguration
- Wrong gateway
- Serial Communication Issues
Data Logger Issues
The data logger concentrates and collects all of the data from the field devices (inverters, meters, MET sensors, etc.) and logs it into a format that can be analyzed.
There are three common issues that can occur with data loggers:
- Data loggers have limitations in terms of how many devices they can talk to. Trying to pull data from too many devices may slow down the overall throughput.
- Data loggers that are based on Windows may experience another problem. The data logger itself won’t restart automatically without the right BIOS settings assigned if a power event results in a restart on the PC the data logger is installed onto. In order to prevent your DAS from unintentionally losing data logger functionality after a PC restart, you should be aware of this and test for it.
- The device ports must be set up with a Modbus communication protocol and use an RS485 or RS232 connection for the data logger to be able to communicate with the other devices. The data logger won’t be able to pull data from the device if it is not configured properly.
Meteorological station issues
Meteorological sensors help gauge the expected performance of the site based on weather conditions. Standard measurements for DAS sites include global horizontal irradiance (GHI), plane of array (POA), back of module (BOM) temperature, ambient air temperature, wind speed and wind direction. Typically, these sensors are part of a meteorological (MET) station.
When it comes to DAS installation, MET stations can be a little challenging. DAS MET station problems can occur on the hardware and programming sides. While some employ digital sensors that support the Modbus protocol, some solely rely on analog sensors. Hard-wired inputs and outputs included into some data loggers make it much simpler to interface with analog sensors. For sensors that work with Modbus, all of the sensors are wired together to form a hub that is then linked to the data logger.
Programming Issues
When the same sensor is utilized several times within the same hub, programming problems are common. Alternatively, due to the interchange on the field, sensors installed on two different MET stations may end up using the same ID and connecting to the same MET station. Due to the conflicting IDs caused by this, even more sensors are unable to connect to the system.
Hardware Issues
The system won’t be able to read data from a sensor if two distinct channels are used in the same sensor.
Sensors can be harmed by power surges if they are not adequately protected. The fuse must be in good condition, and a surge suppressor must be fitted and connected to the terminal blocks properly. Also, the irradiance sensors are particularly susceptible to grounding problems., so it is important to check them.
Cabling Issues
Problems might arise when switching from Ethernet to fiber optic wiring. When the DAS enclosure and field devices are both 300 feet or less apart, Ethernet is sufficient. In order to offer dependable data transfer over long distances as the site expands, fiber optic cabling is required.
To make sure there are no breaks in the fiber along the way and that the right connectors are being utilized between the fiber jumpers and the patch panel and switches, the fiber must go through a number of inspections. Additionally, it is necessary to properly connect the transmitter and receiver terminals.
How to avoid any of these issues?
When it comes to installing DAS systems, you need a team to design and implement the system. From there, you may decide to manage upkeep and maintenance. Another option is to choose a team to design, build, operate, and maintain your DAS system, so you can rest assured that every little detail has been assessed and approved.
As always, feel free to reach out to us for a free consultation.
