3 memory mapping, Bacnet binary input block (0ч60 – 0ч67), Bacnet binary output block (0ч400 – 0ч407) – Spectrum Controls 2080sc-BAC User Manual
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3-18
Chapter 3: Configuring the Module
User’s Manual Pub. 0300274-01 Rev. A.0
(* Write Input Table to Module *)
bacnet_module_address := 112;
bacnet_module_datalen := 8;
bacnet_module_write_fn(TRUE, BACNET_MODULE_SLOT,
bacnet_module_address, bacnet_module_datalen,
bacnet_convert_fn.bac_raw_tbl);
Similarly, for Analog Output, a read operation is performed to read the whole
analog table to
bac_raw_tb
l defined in function block
bacnet_convert_fn
.
Then individual AnalogOutput objects are written to the variable after conversion
from ULINT to a tag data type.
(* Read Output Table from Module *)
bacnet_module_read_fn(TRUE, BACNET_MODULE_SLOT,
bacnet_module_address, bacnet_module_datalen,
bacnet_convert_fn.bac_raw_tbl);
(* 0, AnalogOutput, ao0 *)
bacnet_convert_mode := 0;
bacnet_convert_offset := 0;
bacnet_convert_fn(bacnet_convert_offset,
bacnet_convert_var, bacnet_convert_mode);
tag4 := ANY_TO_INT(bacnet_convert_fn.tmp_raw_var);
3.5.3 Memory Mapping
This section discusses memory mapping between a BACnet module and the PLC.
The BACnet module has internal memory that is mapped to the PLC memory
range. On the PLC, each slot has 2 Kbytes of memory. The internal RAM in the
Module is arranged as below.
This section is for reference only as all the mappings are automatically generated
in the structured text.
BACnet Binary Input Block (0Ч60
– 0Ч67)
Register Name Addr.
Comments
Default
R/W
From PLC
R/W From
Module
BAC_BI
0Ч60 –
0Ч67
BACnet Binary Input data
(tags 0 – 63)
0
W
R
Each bit of the BACnet Binary Input represents a true/false value for one
BACnet Binary Input object. This block supports up to 64 such objects.
BACnet Binary Output Block (0Ч400
– 0Ч407)
Register Name Addr.
Comments
Default
R/W
From PLC
R/W From
Module
BAC_BO
0Ч400
–
0Ч407
BACnet Binary Output data
(tags 0 – 63)
0
W
R