Appendix D How to Use PLC Function
VFD-E Series
D-4 Revision August 2006, 01EE, SW--PW V1.03/CTL V2.03
6. 1000 ~ 9999 display: It will only display the first 3 digits. The LED at the bottom-right
corner will light to indicate 10 times of the display value. For example, the actual value for
the following figure is 100X10=1000.
7. 10000~65535 display: It will only display the first 3 digits. The LED at the bottom-right
corner and the single decimal point between the middle and the right-most numbers will
light to indicate 100 times of the display value. For example, the actual value for the
following figure is 100X100=10000.
D.3 Edition Explanation of Ladder Diagram
Ladder diagram is a diagram language that applied on the automatic control and it is also a diagram
that made up of the symbols of electric control circuit. PLC procedures are finished after ladder
diagram editor edits the ladder diagram. It is easy to understand the control flow that indicated with
diagram and also accept by technical staff of electric control circuit. Many basic symbols and
motions of ladder diagram are the same as mechanical and electrical equipments of traditional
automatic power panel, such as button, switch, relay, timer, counter and etc.
The kinds and amounts of PLC internal equipment will be different with brands. Although internal
equipment has the name of traditional electric control circuit, such as relay, coil and contact. It
doesn’t have the real components in it. In PLC, it just has a basic unit of internal memory. If this bit is
1, it means the coil is ON and if this bit is 0, it means the coil is OFF. You should read the
corresponding value of that bit when using contact (Normally Open, NO or contact a). Otherwise,
you should read the opposite sate of corresponding value of that bit when using contact (Normally
Close, NC or contact b). Many relays will need many bits, such as 8-bits makes up a byte. 2 bytes
can make up a word. 2 words makes up double word. When using many relays to do calculation,
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