司马光中学
Subject: Differences between Modbus and Memobus
Further Documentation:
This document describes the difference between Memobus and Modbus. For additional detailed information, plea refer to the following documents:
•SIE-C815-13.60E “Memobus Descriptive Information”
•SIEZ-C887-1.2 “Machine Controller MP9xx Ladder Programming Urs Manual” Memobus Basics:
When communicating with an MP9xx ries controller and an HMI, the HMI should be the master, and the MP9xx should be the slave. Up to 63 slaves can be addresd using Memobus. The DEFAULT H
MI Driver protocol ttings are as follows:
Transmission rate: 19.2 kbps
Transmission mode: RTU (Remote Terminal Unit)
Data: 8 bits
Parity Check: Even parity
Stop bit: 1 bit
Error Check: CRC-16 (Cyclic Redundancy Check)
Transmission: Half duplex, asynchronous
MP9xx Port: port #2
Slave Address: 1
The MP9xx controller will u a message receive function called “MSG-RCV” in slave mode. This fu
nction accepts standard Modbus function codes in its messaging format. Note that physical hardware outputs are not supported by the Memobus protocol. This is for safety and to avoid conflicts due to unplanned writing of direct control outputs between the HMI and MP9xx ladder program.
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The HMI Driver should support the following function codes for the MP9xx ries controllers:
雄激素过高的症状Function Code Register Description Max QTY per
99什么意思Query message
01H MBXXXXXX Read Bit Condition 2000
02H IBXXXXX Read Physical Hardware Input 2000
03H MWXXXXX Read Contents of Holding Register 125
04H IWXXXX Read Contents of Physical Hardware
Input Word
125
05H MBXXXXXX Write to Single Bit 1
06H MWXXXXX Write to Single Holding Register 1天狗小说
08H - Loop-back
test -
09H MWXXXXX Read Contents of Holding Register
(expanded)
252
0AH IBXXXXX Read Physical Hardware Input (expanded)252
0BH MWXXXXX Write to Multiple Holding Register
(expanded)
251
0DH MWXXXXX Discontinuous read of holding register
(expanded)
0EH MWXXXXX Discontinuous write of holding register
(expanded)
0FH MBXXXXXX Change conditions of multiple bits
(expanded)
10H MWXXXXX Write to Multiple Holding Register 100
Memobus Key Features and differences:
Memobus esntially us the Modbus protocol. The difference lies in how the MP ries controllers interprets the registers. HMI Memobus Drivers should be written with the following considerations:
1) The HMI Memobus driver for the MP9xx ries controller should appear in the driver lection
list labeled as “Memobus” and “Yaskawa MP Series Controllers”. Driver version number should also be readily available.
2) Bits (1 bit), Words (16 bits), and Long Words (32 bits), and Floating Point words (32 bits) take
up the SAME address space (unlike straight Modbus).
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双木不成林Example: MB000001=1 is same as MW00000=1 is same as ML00000=1. This means that
0XXXX coils, 1XXXX input relays, and 3XXXX input registers do not exist.
3) Register numbers are to be mapped directly (no offt).
Example:
Memobus Modbus
MW00000 = 40001
MW00040 = 40041
4) All bits are to be t up in rever order, and expresd in hex.
Address range: MB000000 to MB32767F
Value range: on or off (example MB00000F=1 and MB00000F=0)
For example, MB000300 is register MW00030 bit 0 in the MP9**.
MP9** bit 0 = Modbus bit XXXXX.16
MP9** bit F = Modbus bit XXXXX.1 (Note: bit 15 is t up in the MP9** as hex bit F )
Example:
Bit numbers in MP9** register = 0 1 2 3 4 5 6 7 8 9 A B C D E F Bit numbers in the Modbus tag= 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
The Memobus protocol supports individual bit read/write only from address 0 to 4095. Above that address, a bit write to the MP controller requires the HMI driver to (1) read the word which the bit is stored in, (2) mask and t that bit, and (3) rewrite that word to the MP controller.
This ts up a danger of the HMI and the MP controller becoming out of sync and possibly
over-writing if certain precautions are not taken. Programmers must consider this when
assigning bits for read/write usage between the MP9xx and the HMI. It is important to
organize all bits within a 16-bit word to be either a read or a write function only.
5) Word holding registers consist of 16 bits (two bytes) and are written directly. Address is
expresd in decimal.
Address range: MW00000 to MW32767, Value range: -32768 to +32767
See chart below:
Long words consist of 32 bits (two words), high and low words are to be swapped. Address is expresd in decimal.
Address range: ML00000 to ML32766, Value range: -2147483648 to +2147483647 Yaskawa Electric America - 2121 Norman Drive South – Waukegan IL 60085
Example for MP930:五月开花
ML00100 consists of MW00100 (low word) and MW00101 (high word)
See chart below:
6) Floating point words are 32 bits and are in Intel 486 Single precision format (IEEE Floating
黄槐花Point). The address is expresd in decimal.
Address range: MF00000 to MF32766, Value range: +/- (1.175E-38 to 3.402E+38),0
Intel 486 single precision format: Bit 31=sign, bit 23-30 is biad exponent, bit 0-22 is
significant.
All MP Series products round to display real numbers (floating point) to display 7 digits (if the 8th digit is 5 or greater, then the 7 digit is rounded up).
7) Input registers are accessible for direct monitoring at the HMI. IB, IW, IF. Address is
expresd in hex.
Address range (MP940): IW0000 to IW07FF (2048 decimal)
Address range (MP930): IW0000 to IW0FFF (4096 decimal) – U this as the maximum value.
8) Output registers (physical output points) are not accessible in Memobus.
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9) Field entries in HMI should be auto-configurable when the data type is detected after ur
entry.
董明珠个人简短经历
Data type Default # digits Default Display
Bit Bit 1
Word 6 Signed 16-Bit
Long word 11 Signed 32-Bit
Floating point word (real) 11 Floating point with exponent
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