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CTI Janus Programmable Automation Controller IOG
3.1.2
Electrical Interference
Electrical interference conducted directly through wiring or inducted via electromagnetic coupling can adversely
affect the operation of control equipment. The major sources of electrical interference in an industrial
environment are devices that use high voltages and current, such as motors and welders.
The Janus Controller is designed to meet or exceed IEC standards for immunity to electrical interference. However,
care must be taken to ensure the control equipment is exposed to devices that serve as major sources of electrical
interference devices. To ensure a reliable control system, you will need to determine the source of the electrical
interference and employ suitable techniques to reduce its effect on the control system.
3.1.3
Grounding
It is very important that the all equipment is properly grounded. Lack of proper grounding may cause intermittent
or erratic operation or may cause the control system to fail. A properly installed grounding system will provide a
low-impedance path to earth ground, which will give all PLC internal filtering devices a good ground return for
reference. The earth ground of the building site typically provides reliable grounding; however, if excessive ground
current is present, a separate grounding electrode should be installed.
A common practice is to provide a central ground bus bar as a single point of reference within each enclosure,
connecting all chassis and power supply components to the bus bar. The bus bar is then connected to earth
ground. When connecting to the bus bar, use 1-inch copper braid or No. 8 AWG wire. To ensure good connections,
scrape paint or other non-conductive coatings away from mounting studs and from enclosure surfaces where
mounting bolts and washers make contact.
In addition to connecting the controller chassis and power supply to earth ground, you must ensure that the power
supply, controller and all modules installed in the base are installed securely and that the thumbscrews are
tightened.
3.1.4
Choosing the IP Address and related Parameters
Before you can use the Ethernet port, the controller must be configured with network parameters, including IP
address, network mask, and the default gateway. If you already have a network installed, you should contact your
network administrator to determine the values to be used. See APPENDIX B: IP ADDRESS INFORMATION for more
information on choosing an IP address. See
and
for information on setting the network
parameters.
3.1.5
Power Requirements
The Janus controller consumes 10 watts of +5 VDC power. To calculate the total power required for the base, you
need to add the power requirements for the other modules you will install in the base.
