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Version 3.1 by Theodore Xu on 2023/11/27 17:33
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Theodore Xu 3.1 1 == 1.Modbus ==
Theodore Xu 1.1 2
Theodore Xu 3.1 3 **Communication specifications**
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Theodore Xu 1.1 5 |(% colspan="2" %)Item|Content
6 |(% colspan="2" %)Communication protocol|Modbus protocol
7 |(% colspan="2" %)Standard specifications|Modbus-RTU slave station communication protocol
8 |(% colspan="2" %)Maximum connections|247
9 |(% colspan="2" %)Topological structure|Bus type
10 |Slave station function|Number of messages that can be received and requested at the same time|1
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Theodore Xu 3.1 12 **Hardware configuration**
Theodore Xu 1.1 13
14 |Terminal identification|Terminal name|Function description|Jumper/dialing position
15 |J5|485 communication terminal resistance setting jumper|Match terminal resistance|(((
16 (% style="text-align:center" %)
17 [[image:modbus 跳线帽.png]]
18 )))
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20 Modbus communication port of this product is located on the control panel, as shown in the following figure:
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23 (% style="text-align:center" %)
24 [[image:modbus 电路.png]]
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26 **RS485 Connection Topology**
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28 RS485 bus connection topology is shown in the following figure. 485 bus is recommended to use shielded twisted pair (STP), 485+, 485-: Adopt twisted pair to connect; Only 120 Ω terminal matching resistors are connected at both ends of the bus to prevent signal reflection; All node 485 signal grounds are connected together; Connect 128 nodes at most, and the distance between branches of each node should be less than 3m.
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30 **Multi-node connection mode**
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32 When the number of nodes is large, 485 bus must be daisy chain connection. If branch connection is needed, the branch length from bus to node had better be short. It is recommended that it should not exceed 3m. **Star connection should be forbidden**. The diagram of common bus structure is as follows:
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Theodore Xu 2.1 34 Figure1 Daisy chain connection
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Theodore Xu 1.1 36 (% style="text-align:center" %)
37 [[image:菊花链接.png||alt="Daisy chain connection"]]
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Theodore Xu 2.1 39 Figure2 Branch connection
Theodore Xu 1.1 40
41 (% style="text-align:center" %)
42 [[image:分支链接.png]]
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Theodore Xu 2.1 44 Figure3  Star connection **(Forbidden) **
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Theodore Xu 1.1 46 (% style="text-align:center" %)
47 [[image:星型链接.png]]
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Theodore Xu 2.1 49
50 **Transmission distance**
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52 The maximum number of nodes and transmission distance supported by our standard RS485 circuit at different rates are shown in the following table.
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54 |Transmission distance (m)|Rate (kbps)|Number of nodes|Wire diameter
55 |100|115.2|128|AWG26
56 |1000|19.2|128|AWG26
Theodore Xu 3.1 57
58 == 2.PNP/NPN ==
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60 === VM series ===
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62 (% class="box infomessage" %)
63 (((
64 ✎Note:VM series manufactured after April 2023 can support this feature.
65 )))
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67 NPN/PNP switching has been added to the VM series machines, enabling fast switching between the two modes.
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70 (% style="text-align:center" %)
71 [[image:原理图.png]]
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73 The NPN/PNP mode can be switched manually at the illustration to realize the compatibility of external signals. Where the upper two pins are shorted for NPN, the lower two pins are shorted for PNP mode.
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75 **Product model**
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77 0.75~~2.2(KW)
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79 (% style="text-align:center" %)
80 [[image:VM小功率.png]]
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82 4~~7.5(KW)
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84 (% style="text-align:center" %)
85 [[image:VM大功率.png]]
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