H 7 - 3
F B
S
- X X M N
7.2
5VDC Ultra High Speed Line-Driver Differential Output Circuit and its Wiring
The 5VDC ultra high speed Line-Driver differential output circuit of FB
S
-PLC is only available for the main unit of the
MN model. Its output can connect to general photo coupler circuit or Line-Receiver input circuit, with the connection
shown in the figure below. To improve noise immunity and maintain signal quality, please use twisted pair with shield (or
aluminum foils) for connection and connect the shield with SG of PLC and FG of the driver. Please also operate in
2-phase driving mode (because 2-phase driving can automatically cancel interferences from noise pulses).
FB
S
-MN
主機
雙絞線
Line-Driver
輸 出
Photocouple
輸入之範例
Line-Receiver
輸入之範例
負載
7.3
Single-End Output Circuit
Except that the 5VDC ultra high speed output circuit has independent dual terminal outputs, all other output circuits
such as relays, transistors or TRIAC are single-end output structure. A single-end output in each digital output (DO)
takes up only one terminal. But since any output device has two ends, the one end of several output devices have to be
connected together to one common point (called output common) for single-end output. Then each output point can
output via this common point. The more output device share a same common points, the more terminals are saved,
while relatively increasing the current running through the common point. Combination of any output common with its
individual single-end outputs are called a Common Output Block, which is available in 2, 4 and 8PTs (high-density
module) in FB
S
-PLC. Each Common Output Block is separated from one another. The common terminal has a label
initiated with letter “C”, while its numbering is determined by the minimum Yn number which comprise the output block.
In the example of the figure below, the number of common terminal of output block Y2 and Y3 is C2, while the number
of common terminal of output Block Y4, Y5, Y6 and Y7 is C4. The various single-end common output circuits are
described below
：
7.3.1
Structure and Wiring of Single-End Relay Output Circuit
Because relay contacts have no polarity, it can be applied for AC or DC load power. Each relay can provide current up
to 2A. The maximum rated current in all output commons of FB
S
-PLC is 4A. Its mechanical lifetime can reach up to 2
million times, while the contacts have a shorter lifetime. The lifetime also varies depending on working voltage, load
type (power factor cos
ψ
) and contact current. The relation between them is plotted in the figure below. In the case of
pure resistive load (cos
ψ
=1.0) at 120VAC and 2A, the lifetime of contacts is about 250 thousand times. While for high
inductive or capacitive load with cos
ψ
up to 0.2 and current within 1A, the lifetime decreases rapidly to about 50
thousand times (AC200V) or 80 thousand times (AC120V).
Photocouple input
Line-Receiver input
Load
FB
S
-MN Main
Unit
Line-Driver
Output
With frequency up to 920KHz, for high speed or high noise environments
Twisted-pair
