External Address
is an ascii
string which exactly references an item of data within the PLC. It can be entered at configure time as
a text string, and will be validated by the system before use. For this protocol the External
Address has the following format:
N - Dec number 0 - 9
Type
Offset
RU
NN
RD
NN
SW
NN
SQ
NN
RN
NN
CX
NN
CP
NN
CN
NN
CB
NN
CW
NN
CD
NN
Offset Format
The software also allows
an item of data within the PLC to be referenced by means of a table selection and an offset. The following
table shows the offset and table formats for the simulation:
Table
External Address Type
Type
Offset Format
Offset Range
Privilege
R = Read W = Write
Description
RU
RU
Word
NN
00-49
RW
Ramp Up
RD
RD
Word
NN
00-49
RW
Ramp Down
SW
SW
Word
NN
00-49
RW
Sine Wave
SQ
SQ
Word
NN
00-49
RW
Square Wave
RN
RN
Word
NN
00-49
RW
Random
CX
CX
Bit
NN
00-49
RW
Bit Counter
CP
CP
Packed Bit
NN
00-49
RW
Packed Bit Counter
CN
CN
Nibble
NN
00-49
RW
Nibble Counter
CB
CB
Byte
NN
00-49
RW
Byte Counter
CW
CW
Word
NN
00-49
RW
Word Counter
CD
CD
dWord
NN
00-49
RW
dWord Counter
Property Pages
No property
pages exist for this protocol
Protocol Compatibility
The bit type tables ‘CX’ and ‘CP’ will support the configuration of
point types bigger than a bit. If a publication point is configured for example, 16 bits will be read
from the table to fill the point. From the users perspective these two tables are exactly the same, the
difference between ‘bit’ and ‘packed bit’ data types is in the way the protocol returns information to
the application level.
The nibble, byte, word and dword type tables all support the configuration
of smaller or bigger point types. All larger point types will read the required number of data units to
fill the point. Smaller type points will scale down the data to fit it into the point. Bit type points
allow the selection of a bit offset to reference the required bit from the data unit. In the case of bit
selection points, drive outs will perform a read/modify/write operation as the protocol does not support
a bit set operation in this case.
Each of the tables have 50 simulated values, which will vary in different
ways depending on the simulation type. Driving out to these values will cause the simulation to shift
and continue from the new value. For example a counter simulation counting 1, 2, 3, 4…etc, driving out
a value of 100 will cause the simulation to continue 101, 102, 103…etc.
A simulated value is changed every time a read operation is performed.
If more than one point is configured that makes use of the
same simulated address, then the expected simulated results may not be received.
The following shows
mathematically how the simulated results are achieved for each table:
N = Offset
X = New Value
T = Tick number
A = Angle in radians
Simulation
Formula
Ramp Up
X = T * (N + 1)
where T = 0
10
Ramp Down
X = T * (N + 1)
where T = 10
0
Sine Wave
X = sin(A) * (N + 1)
where A = 0
2p
increasing in steps of 0.1 radians
Square Wave
X = 0 then X = 10 * (N + 1)
Random
X = RAND(65535)
where RAND is a random function, values 0-65535
Bit Counter
X = X + 1, 0<= X <= 1
Packed Bit Counter
X = X + 1, 0<= X <= 1
Nibble Counter
X = X + 1, 0<= X <= 12
Byte Counter
X = X + 1, 0<= X <= 255
Word Counter
X = X + 1, 0<= X <= 65535
dword Counter
X = X + 1, 0<= X <= 4294967295
All simulations repeat continually after completion.
Port Settings
No physical connection
is required, the protocol is a simulation.
Wiring Information
No physical connection is required, the protocol is a simulation.
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