Technical data

Addresses Memory area
Table 9-4 continued:
8000H to DD7FH
DD80H to E3FFH
E400H to E7FFH
E800H to EDFFH
EE00H to EFFFH
F0000H to FFFFH
System RAM:
DB-RAM (16 bits)
DB 0 (16 bits)
S flags (8 bits)
System data (16 bits: BA, BB, BS, BT,
timers and counters)
RAM (8 bits: flags, process image)
I/Os (8 bits)/S5 bus
Sequence The field transfer is made in descending order, i.e. it begins with the
highest address of the source area (= end address) and ends with the
lowest.
Use in the page area The TNB and TNW operations are not suitable for accessing the page
area (addresses F400 to FBFF) in the S5-135U multiprocessor PLC.
Use instead the operations from Section 9.4.4 "Accessing the Page
Memory" or the special functions from Section 6.2.1 "Page Accesses".
Special features
Pseudo operation boundaries
with TNB and TNW
The TNB and TNW operations are long-running STEP 5 operations
that contain so-called "pseudo operation boundaries". This means that
the data is transferred in sub-fields of various sizes depending on the
source and destination area. If an error (e.g. cycle error) or an
interrupt (e.g. caused by a time or process-driven interrupt) occurs
during the transfer of a sub-field, the appropriate organization block is
inserted at the end of this sub-field. This is, however, only possible if
DX 0 is programmed to allow interruptions at operation boundaries.
If one or more timeouts and/or addressing errors occur during the
transfer, all the sub-fields are transferred first and then before the next
operation is executed, the appropriate error organization block is
called once (if QVZ and ADF occur simultaneously, only the
QVZ-OB is called). The error address specified is always
the address
at which an error occurred
first. Since TNB and TNW operate with
decrementing addresses, when there is more than one error, this is
always the
highest error address in the area in which an error first
occurred. OB 2, OB 10 to 18 or an error organization block can be
inserted at the pseudo operation boundaries.
9
Transferring Fields of Memory
CPU 928B Programming Guide
C79000-B8576-C898-01
9 - 19