FOXBORO RH916XZ DCS module

Description

For TAs that provide group isolation (RH916CA, RH916XZ, P0916CB, and P0916PX) input channels are group isolated from ground. For details, see Standard and Compact 200 Series Subsystem User’s Guide (B0400FA). These module/TA combinations can withstand, without damage, a potential of 600 V ac applied for one minute between the group isolated channels and ground.

Interference from power supply
The normal power supply controlled by the PLC system is powered by the power grid. Due to the wide coverage of the power grid, it will be subject to all spatial electromagnetic interference. The radiated electromagnetic field (EMI) in space is mainly generated by transient processes of power networks, electrical equipment, lightning, radio broadcasting, television, radar, etc., commonly known as radiation interference. If the PLC system is placed in the RF field, it will receive radiation interference and induce voltage on the line. Especially the changes within the power grid, such as surges caused by knife switch operation, start-up and shutdown of large power equipment, harmonics caused by AC and DC transmission devices, and transient impacts caused by power grid short circuits, are all transmitted to the power source through transmission lines. It may cause program errors or arithmetic errors, resulting in erroneous input and output, which will cause equipment loss of control and malfunction, and thus cannot guarantee the normal operation of the PLC.

The various signal transmission lines connected to the PLC control system, in addition to transmitting effective signals, will always have external interference signals invading. There are two main ways for this interference: firstly, it is caused by power grid interference connected in series with the power supply of the transmitter or shared signal instrument; The second is that the signal line is interfered by spatial electromagnetic radiation induction, which causes many system failures.
Interference of grounding system
Grounding is one of the effective means to improve the electromagnetic compatibility (EMC) of electronic equipment. Proper grounding can not only suppress the impact of electromagnetic interference but also suppress external interference from equipment; However, incorrect grounding can actually introduce serious interference signals, making the PLC system unable to function properly.

Frequency converter interference
One is that harmonics generated during the start-up and operation of the frequency converter cause conduction interference to the power grid, causing voltage distortion and affecting the power supply quality of the power grid; The second is that the output of the frequency converter will generate strong electromagnetic radiation interference, which affects the normal operation of surrounding equipment.

Suppression of power interference
Generally, protection is achieved by setting shielded cables, PLC local shielding, and high-voltage relief components. Selecting equipment with good isolation performance, selecting excellent power sources, power lines, and signal lines should be more reasonable. For main components such as power transformers, central processing units, and programmers, conductive and magnetic materials should be used for shielding treatment to prevent the influence of external interference signals. Power adjustment and protection: Voltage distortion or burrs caused by power fluctuations will have adverse effects on PLC and I/O modules.

The+5V power supply required for the core components of the microprocessor is processed through multi-level filtering and adjusted using an integrated voltage regulator to adapt to the fluctuations of the AC power grid and the effects of overvoltage and undervoltage. Try to run the power lines parallel as much as possible, with low impedance to ground to reduce power noise interference. The grounding method of its shielding layer is different, and the interference suppression effect is different. Generally, the secondary coil cannot be grounded. The input and output lines should be twisted pair and the shielding layer should be reliably grounded to suppress common touch interference. In addition, a 1:1 isolation transformer with a shielding layer can be installed to reduce interference between the equipment and the ground. LC filtering circuits can also be connected in series at the power input end.

MAX-4/11/03/128/99/0/0/00
MAX-4/11/03/128/08/1/1/00
MAX-4/11/03/128/04/1/1/00
MAX-4/11/03/032/99/1/1/00
MAX-4/11/03/032/08/1/1/00 1313
MAD130C-0150-SA-S2-BK0-05-N1
MAC112A-0-VD-1-B/130-A-1/-1006
MAC093B-0-OS-2-C/130-A-0/S005
MAC090C-1-GD-1-B/110-A-2/I0062
MAC090C-1-GD-1-B/110-A-1/-I006
MAC090C-0-KD-4-C/110-B-0/D1524