DUEMMEGI
MCP 4 – User's manual
Contatto
FIELDtoRAM
= (
O20.3
, \
O20.4
, \
AO1
,
AO2:3
, \
O21:1.1..O21:1.8
)
The alignment from field to RAM, however, is not allowed for all types of modules; when allowed, the related
technical sheet of the module will specify this, together to some suggestion on the best setting. Remember
that, unless otherwise specified in the
FIELDtoRAM
equation, the alignment will be always executed from
RAM to field.
2.1.11- Data exchange between MCP 4 controllers
If more MCP 4 controllers have been installed in a plant, it is possible to activate feature allowing to exchange
of data among them. To do this, simply connect each MCP to the other, in order to create a RS485 network
(exclusively using COM2 port), and instruct each MCP 4 belonging to this network to “publish” the data well
specified by proper directives; therefore, non more components are needed in addition to the RS485 cable
connecting the installed MCP 4 controllers.
Moreover, the data exchange mechanism here described also applies between
Contatto
MCP 4 controllers
and
Domino
DFCP controller, allowing interactions between the two systems.
The information that can be published on the network are the virtual points and the registers and therefore,
since any digital or analog variable can be supported by these ones, almost any information regarding each
MCP 4 or the modules connected to it can be transferred.
Each MCP 4 can publish a maximum of 125 Words; since each register takes 1 Word and a Word can
contains 16 contiguous virtual points, as an example the following combinations are allowed:
2000 virtual points - 0 registers
1000 virtual points - 62 registers
512 virtual points - 93 registers
0 virtual points - 125 registers
In other words, the number of virtual points divided by 16, added to the number of register, must be less or
equal to 125:
(nr.V) / 16 + nr.R <=125
As said before, the data exchange feature among more MCP 4 controllers must be activated, during
programming step, by one or more configuration directives specifying how many virtual points and/or
registers have to be published. These configuration directives are as follows:
NETWORK
= (Vstart .. Vstop)
NETWORK
= (Rstart .. Rstop)
Vstart and Vstop means respectively an initial and a final virtual point; any value chosen as Vstart and Vstop
will be however forced as multiple of 16 by the compiler of MCP IDE; for instance, choosing
V3..V9
, the
compiler will force
V1
..
V16
.
Rstart and Rstop means respectively an initial and a final register; these two values can be set as desired,
but remembering that the total number of Words that can be published (virtual points and registers) must be
less or equal to 125 as said before.
Each MCP 4 belonging to the network will write in its memory the information published by the other MCP 4
controllers; each Word will be stored in the same position from which it has been originated, therefore the
content of register R50 of a MCP 4, for instance, will be stored as R50 by all other MCP 4 controllers. For this
reason, of course, the Words published by each MCP 4 must be different from one to the others; in other
words, it is mandatory to avoid superimposition of the Words published by the controllers belonging to the
same network.
DUEMMEGI
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www.duemmegi.it
Rel.: 1.2 October 2018
Page 13 of 87
