Watlow PM LEGACY PM3, Руководство пользователя

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Watlow PM LEGACY™ Limit Controller
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Appendix
Modbus - Programmable Memory Blocks
The Modbus assembly or programmable memory blocks consists of 40 pointers to the parameters of
your choosing starting at Modbus register 40 (shown on the following page). The pointers are 32-bits
long and are stored in two sequential registers. As an example, if it is desired to move an alias to the
Analog Input of the PM (register 360) into pointer registers 40 and 41, a single multi-write command
(0x10 function) would be used writing 360 into register 40 and 361 into register 41.
Once the parameters of choice have been defined and written to the specified pointer registers, the
working registers will then represent the parameters written. In the example above, the 32-bit floating
point analog input (360 and 361) was first written to registers 40 and 41 which in turn defines working
registers 200 and 201 as Analog Input 1. As can be seen in the far right-hand column in the graphic
above, reading back registers 200 and 201 the temperature, as detected by the first analog input is
displayed.
The screen shot above was taken from a program that can be found on the Watlow Support Tools
DVD (shipped with the product) as well as on the Watlow website. On the DVD, it can be found under
“Utility Tools” and is identified as “Modbus TCP Diagnostic Program for PM LEGACY™ Limit, RM and
ST”. A similar program can be found here as well for Modbus RTU. If it is easier to go to the web to
acquire this software, click on the link below and type “modbus” in the search field where both ver-
sions can be found and downloaded.
http://www.watlow.com/en/resources-and-support/Technical-Li-
brary/Software-and-Demos