Remote Processing CX-10 - Manual (Page 40)

Appendix A CX-10 Modbus Map
Appendix A Modbus Map Page 7
Volatile Operating System
These are integer (16 bit) types. Function code 3 reads, 16 writes. Not all registers allow read, write, or read and write.
Address range is 4701 to 4800. This group of registers dictate certain operating system functions. They are volatile and
will generally return a 0 on power up or reset.
NOTE: These registers are not accessible via modbus port. They are accessible only through Basic.
Unless you will be putting the CX-10 into master mode and running in Basic, these registers will not be of interest.
Register Read/Write Permission Detail
4701-4779 No read/write. Returns
error Reserved. Any read or write returns an error.
4780 Read/write Contains status of PCON register when CPU resets
4781 Read only COM 3 - number of buffer variants. See discussion below for this register.
4782 Read only COM 3 - Read variant from buffer. See discussion below for this register.
4783 Read only COM 3 - Master & slave mode status. See discussion below for this
register.
4784 Read only Returns 0
4785 Read only Returns 0
4786 Read only Returns 0
4787 Write only Reset CPU. Writing the value 43605 (0AA55H) to this register causes a
CPU reset.
4788
4789 Write only Clear COM 3 receive buffer and reset master/slave status. Writing 43605 to
this register flushes the receive buffer.
4790-4800 Read/write Reserved
Register 4781 operating detail
This register returns the number of variants (bytes, integers, floats) of data are available to read via register 4785. This
registers will contain a value immediately after a successful modbus PRINT #3 is executed and a good response has been
recieved (register 4783 = 5). Reading register 4782 decrements this register by 1.
NOTE: All data must be readfrom the buffer (regiser 4784 = 0) to reset the buffer for another transaction or a valid write
to register 4789 to clear the buffer.
The term ‘Variants’ means any valid numeric value. This can be a bit, byte, two bytes (integer word), or four bytes (float)
long. Values will be returned, via register 4782, in their normalized state. Basic automatically interprets these values and
returns the normalized value.
Register 4782 operating detail
This register returns variants (bytes, integers, and floats) as the result of a master read or write. Data is read sequentially in
modbus order (ID, type, length, ect) based on original modbus function code. Thus, you have access to the entire modbus
messge.