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This chapter discusses how to troubleshoot problems associated with Foundation Fieldbus (FF). FF is more complicated to troubleshoot than most networks because it can, and often does, use the communication bus to power devices. The troubleshooter needs to know not only whether the communication is working but also whether there is enough power for the devices. When troubleshooting a Foundation Fieldbus system, it is necessary to first determine whether the problem is a power problem or a communications problem. In new systems, it may be found that the problem is both. In working systems it is usually one or the other. Power problems in a FF system can be divided into two types: one where the system is new and never worked and the other where the system has been up and running for a while. The easiest way of determining a power problem: check each device to see if the power light is on; measure the voltage at each device; check the connections for opens, corrosion or loose connections; and measure the current draw of each device to see if it conforms to the manufacturer's specifications. One of the best troubleshooting tools for FF is the LEDs provided on the devices. These LEDs show many different conditions of the system. |
