Siemens SINUMERIK 840DE sl Commissioning Manual page 958

Functionality
5.3 Variable access
Examples of variable paths (PLC access operations)
Table 5-3 Examples of variable paths (PLC access operations)
Variable path
/Plc/M5.0
/Plc/DB5.DBW2
/Plc/DB8.DBB2:STRING
/Plc/DB8.DBW2:[10]
/Plc/DB100.DBB1
/Plc/DB2.DBD0:REAL[10]
Note
● Timers can only be read. A timer is active if it contains a value other than 0.
● If the data type CHAR or STRING is used in conjunction with a byte access, UTF8
characters are read, but if either data type is used in conjunction with a word access, UTF16
characters are read.
● Variables of the STRING type contain the maximum length in the first byte and the actual
length in the second byte. When strings are written, the actual length is adapted accordingly.
The maximum length is not changed.
● For the STRING data type in conjunction with a byte access (e.g. "/Plc/
DB99.DBB0:STRING"), the maximum string length is 255 characters. As a result of the
UTF8 formatting, for some characters (e.g. for the "µ"), two bytes are required so that the
maximum string length is correspondingly reduced.
● Only one-dimensional arrays are supported.
5.3.4 Variable paths for machine and setting data
The variable paths for machine and setting data are stored in the address space of the
SINUMERIK Operate OPC UA server under the nodes "/Sinumerik/TEA" and "/Sinumerik/
SEA". Pay attention to the correct upper-case and lower-case of the "nodeID". The respective
identifier of the "nodeID" provides information on the correct notation.
The displayed machine and setting variables always represent only the first parameter of the
corresponding data area (channel, axis).
Table 5-4
Variable path
/NC/_N_CH_TEA_ACX/$MC_CHAN_NAME
/NC/_N_CH_TEA_ACX/$MC_CHAN_NAME[u2]
Machine data arrays are 1-indexed for access.
42
Description
Memory bit 0 at byte offset 5
Word (16-bit) at byte offset 2 in data block 5
UTF8 string beginning at byte offset 2 in data block 8
Array of 10 words beginning at byte offset 2 in data block 8
Byte at byte offset 1 in data block 100
Array of 10 double words (32-bit) beginning at byte offset 0 in data block 2, which are
formatted as a floating-point number
Examples of variable paths (machine and setting data)
SINUMERIK Integrate for Engineering Access MyMachine / OPC UA
Configuration Manual, 12/2017, 6FC5397-1DP40-6BA1
Description
Channel name of channel 1
Channel name of channel 2