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2.3
Link 7000 Series Modules to Ethernet
The 7000 family was originally designed for RS-485 network. Therefore,
they are very robust and work well under the harsh environments of industry.
Sometime, users need to link the 7000 family modules to Ethernet network.
The possible solutions are given as follows:
Using VxComm technology
Using Xserver technology
The VxComm approach provides a MS-COMM-compatible interface.
Therefore, the old programs may work without any modification. However, it
is also limited by MS-COMM as follows:
Step 1: Sends command to module 1
Step 2: Reads response from module 1
Step 3: Sends command to module 2
Step 4: Reads response from module 2
……………………………………….
Step N: Sends command to module M
Step N+1: Reads response from module M
Step N+2: Computes results
Step N+3: Gos to step 1 for next loop
It is observable, the VxComm approach makes program read/write data
one-by-one. If there are 100 sets of 7000 modules installed in the RS-485
network, the VxComm approach must read/write every 7000 module one by
one. So it will take a long time. The drawbacks of this approach are given as
follows:
It may take long time if there are many 7000 modules installed in the RS-
485 network
All 7000 modules are slave devices, so they cannot take action in case of
emergency event (the host-PC fails).
The Xserver approach provides a TCP/IP protocol interface, so user can
design a client using the popular TCP/IP protocol interface. The most
important feature is that the Xserver can link to TCP/IP clients and controls
7000 modules without any help of client programs. In other words, the Xserver
is designed to solve the 2 problems that occur in the VxComm approach..
7188E Series Hardware User’s Manual, 2004, v2.2, 7MH-016-22 ----- 18