5 Operation
5-34
CJ-series PROFIBUS Master Unit Operation Manual for NJ-series CPU Unit (W509)
3
The total size per Input/Output area can be found for each area, next to the CPU memory area
selection box (for example, the figure above; Output area 1 occupies 7 words).
Note 1 The CJ1W-PRM21 Master DTM will check whether two or more selected mappings in the
CPU memory will be overlapping. In that case, the start address set, will be shown in red.
2 If any mapping error is discovered by the Master DTM, an error message is displayed and
download is terminated.
The CJ1W-PRM21 PROFIBUS Master Units perform an interface function between a PROFIBUS
network and the NJ-series controller unit. On both sides of the interface different formats for data
and data storages are used.
To ensure that I/O data transferred through the interface can be used on both sides of the interface
without additional formatting, the CJ1W-PRM21 PROFIBUS Master Units perform the necessary
data formatting. This ensures that I/O data in the CPU memory can be processed by standard CPU
functions and that the I/O data transferred to/from the PROFIBUS DP slaves over the network is
compliant with the PROFIBUS DP definitions.
The table below lists the I/O data formats supported by both the PROFIBUS network and CPU. See
A-6 I/O Data Type Definitions for more information about the conversion of I/O data.
5-5-3 Supported Data Types
Data Type Size [bytes] PROFIBUS DP NJ-series Controller Unit
Single 8-bit Integer
signed/unsigned
1 Supported.
Data is transmitted on a byte-
by-byte basis.
Not supported
Minimum is 16-bit words. Two
bytes will be formatted in one
word. Words containing odd
bytes will be padded with
zeros.
Single 16-bit Integer
signed/unsigned
2 Supported.
Data is transmitted on a
Most-Significant-Byte First
basis.
Supported.
Single 16-bit integers are
transferred to memory words
in CPU memory.
Single 32-bit Integer
signed/unsigned
4 Supported.
Data is transmitted on a
Most-Significant-Byte First
basis.
Supported.
Data is stored with the Least-
Significant-Word at the lowest
address.
Floating point 4 Supported.
Data is transmitted on a
Most-Significant-Byte First
basis.
Supported.
Data is stored with the Least-
Significant-Word at the lowest
address.
Visible string -- Supported.
Length of string is fixed by I/O
configuration. Data is trans-
mitted on a left-to-right basis
(i.e. first character is transmit-
ted first).
Supported.
First characters are stored at
the lowest address. String is
padded with a zero byte or a
zero word, depending on the
number of characters.
Byte string -- Supported.
Length of string is fixed by I/O
configuration. Data is trans-
mitted on a left-to-right basis
(i.e. first character is transmit-
ted first).
Supported.
First bytes are stored at the
lowest address. String is pad-
ded with a zero byte or a zero
word, depending on the num-
ber of characters.
Date / Clock time 7 Supported.
Date/Time format contains
absolute time with respect to
start of century. Date/Time is
coded in individual bytes.
Not Supported.
Date/Time format is trans-
ferred to CPU memory as
string of words.
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