Outputs; Data Transfer Control Bits; Data Identification Bits - Siemens SIMATIC 505 Installation And Operation Manual

Internal Register Structures (continued)

Outputs

3-10 Advanced Function Programming
The discrete output points consist of Y17 – Y32.
Y17 – Y19 are used to identify the data being transferred. As data is loaded
to the module, the state of these bits identifies the type of data being
transferred (see Table 3-6). The SIMATIC 505–2556 module decodes these
bits and processes the data accordingly.
Table 3-6 Data Identification Bits
Y19 Y18
0 0
0 0
0 1
0 1
1 0
In addition, Y27 – Y32 are used to reset averaging, reset valley hold values,
reset peak hold values, read peak or valley values, read flags, and to write
data to the module. See Figure 3-5.
Y27 Averaging reset
1 Resets averaging on all channels to new values loaded
Y28 Valley hold reset
1 Reset valley hold
Y29 Peak hold reset
1 Reset peak hold
Y30 Read peak hold/valley hold
0 Read valley hold values
1 Read peak hold values
Y31 Read peak hold/valley hold or Read flags
0 Read flags
1 Read peak hold/valley hold values
NOTE: In operation, the state of Y31 determines whether WX49 — WX64
return peak/valley data or the flag bits defined in Figure 3 3. If Y31 is on,
then the type of data (valley hold or peak hold) is selected with Y30.
Y32 Data_Ready, controller to module data ready flag
0 no data
1 data ready to transfer
Figure 3-5 Data Transfer Control Bits
Y17 Data Transfer Type
0 No operation
1 Function enable bits
0 Low/High alarm setpoint values
1 Scaling low/high values
Filtering time constant/Number of
0
averages
SIMATIC 505–2556 Installation and Operation Guide