Rockwell Automation 2755 Enhanced Decoder Series B - Manual (Page 273)

16–8 PCCC Host Commands
Publication 2755-833
Read Decoder Configuration Data
Appendix A lists the address location for each configuration
parameter along with the byte size of the data and the default value.
To read or examine one or more parameters, send the read command
with the appropriate starting address and byte size referenced in
Appendix A.
5
1
3
7
0
2
4
6
STS= 00H
Configuration Data Address (300H to 5FFH)
TNS
High Byte Low Byte
MSB LSB
CMD= 01H
Size = n
Read Configuration Data
00H
The reply returns the configuration data at the specified address.
0
5
STS= 00H
TNS
High Byte Low Byte
MSB LSB
1
3 2
4
Reply to Read Configuration Data
Configuration Data
CMD Reply = 41H
You can read more than one parameter, however the read operation
must specify an address within the valid address range and start on a
parameter boundary. If you try to read outside a valid address range,
the reply returns with a status of 10H (invalid address).
The unprotected write command (08H) performs these decoder
functions:
•
Modifies (or writes over) decoder configuration data
•
Executes a decoder function
•
Sends a repeat read command
•
Sends a message to the AUX port terminal and LCD Display
•
Holds a discrete output on or off
Each command modifies (or overwrites) data at a specific address in
decoder memory or executes a specific decoder function. The
following sections define each of the write commands.
Important: If the configuration date is a text string, you must send
the length of the string as the first byte of the string.
Unprotected Write
Command