As you can see we already discussed about some of the Installation & Troubleshooting of some communication systems in part 1 this section will discuss about AS-i,devicenet, ethernet,TCP/IP
if you want to read about part 1 link is given below
The AS-i system has been designed with a high degree of “ease of maintenance” in mind and has a high level of self-diagnosis incorporated. The system is continuously monitored against faults such as:
• Operational slaves errors (permanent or intermittent slave fault, defective configuration data such as addresses, I / O configuration and ID codes)
• Operational master errors (permanent or intermittent master fault, defective configuration data such as addresses, I / O configuration and ID codes)
• Cable operational errors (short circuits, cable breakage, telegrams damaged due to electrical interference and voltage outside the permitted range)
• Slave errors related to maintenance (false addresses entered, false I / O configuration, false identification codes)
• Master errors related to maintenance (projected defective data such as I / O configuration, identification codes, parameters, etc.)
• Maintenance-related cable errors (pole control of the AS-i cable) The fault diagnosis is displayed by LED on the master. Wherever possible, the system will be protected during a short circuit.
Networks, in general, exhibit the following types of problems from time to time. The first type of problem is electronic in nature, where a specific node (for example, a network interface card) malfunctions. This may be due to component failure or incorrect device configuration. The second type is related to the medium that interconnects the nodes. Here, the problems are more often of an electromechanical nature and include open circuits and short circuits, electrical noise, signal distortion and attenuation. Open circuits and short circuits in the signal path are caused by defective connectors or cables. Electrical interference (noise) is caused by an incorrect ground connection, broken shields or external sources of electromagnetic or radio frequency interference. The distortion and attenuation of the signal may be due to an incorrect termination, a breach of the topology guidelines (for example, cables that are too long) or defective connectors. While these are general problems related to the network, the following are very specific to Devicenet:
• Missing terminators
• Excessive common mode voltage caused by defective connectors or excessive cable length
• Low supply voltage caused by defective connectors or excessive cable length
• Excessive signal propagation delays caused by excessive cable length
Ethernet hardware is quite simple and robust, and once a network is started with wiring and professional certification, the network should be fairly free of problems. Most problems will be experienced in the start-up
phase, and theoretically could be attributed to wiring, LAN devices (such as hubs and switches), network interface cards (NICs) or the configuration of the protocol stack on the hosts. The wiring system must be installed and commissioned by a certified installer. This effectively rules out wiring problems for new installations, although old
the facilities may be suspicious. If LAN devices, such as hubs and switches, belong to accredited providers, they are unlikely to work poorly at the beginning. However, care must be taken to ensure that smart (managed) switches and switches are correctly configured.
NICs rarely fail, and nine out of ten times the problem lies in improper configuration or improper installation of the driver or incorrect configuration of higher-level protocols such as IP.
This section deals with problems related to the set of TCP / IP protocols. The TCP / IP protocols are implemented in the software and cover the second (Internet), the third (Host to the Host) and the upper layers (Application) of the ARPA model. These
the protocols need a network infrastructure and a means to communicate. This infrastructure is typically Ethernet. Typical problems of the network layer: if the TCP / IP protocol stack is not installed correctly on the local host (the host can not access the network). The easiest way to confirm this, in addition to checking the configuration of the network through
the control panel and the visual confirmation that TCP / IP is installed for the particular NIC used in the host, is to perform a loop test by pinging the host itself.
This is done by executing local ping host or ping 127.0.0.1. If a response is received, it means that the battery is installed correctly. Other possible problems include:
• A host that does not get an automatically assigned IP address
• Reserved IP addresses
• Duplicate IP addresses
• Incorrect network ID: different netID in the same physical network
• Incorrect subnet mask
• Default gateway incorrect or absent
• MAC address of a device unknown to the user
• IP address of a device unknown to the user
• Incorrect IP address.
Problems of the transport layer: without really going into the detailed treatment of the TCP protocol, there are some simple things that a relatively inexperienced user can verify.
• No connection was established
• Incorrect port number.
Troubleshooting of radio : when solving problems of an existing system, it is worth checking some of the problems that were discussed previously. These are the following:
• Frequency selection
• Interference from other radio equipment
• Intermodulation problems
• Calculation of incorrect route loss
• Radio modems.