DL205 User Manual, 4th Edition, Rev. B
5–206
Chapter 5: Standard RLL Instructions - Modbus
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A
B
C
D
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Exception Response Buffer:
specifies the master memory address where the Exception Response
will be placed (6-bytes in length). See the table on the following page.The exception response buffer
uses 3 words. These bytes are swapped in the MRX/MWX exception response buffer V-memory so:
V-Memory 1 Hi Byte = Function Code Byte (Most Significant Bit Set)
V-Memory 1 Lo Byte = Address Byte
V-Memory 2 Hi Byte = One of the CRC Bytes
V-Memory 2 Lo Byte = Exception Code
V-Memory 3 Hi Byte = 0
V-Memory 3 Lo Byte = Other CRC Byte
MRX Slave Memory Address
MRX Master Memory Addresses
MRX Slave Address Ranges
Function Code
Modbus Data Format
Slave Address Range(s)
01-Read Coil
484 Mode
1-999
01-Read Coil
584/984 Mode
1-65535
02-Read Input Status
484 Mode
1001-1999
02-Read Input Status
584/984 Mode
10001-19999 (5 digit) or 100001-
165535 (6 digit)
03-Read Holding Register
484 Mode
4001-4999
03-Read Holding Register
584/984
40001-49999 9 (5 digit) or
4000001-465535 (6 digit)
04-Read Input Register
484 Mode
3001-3999
04-Read Input Register
584/984 Mode
30001-39999 (5 digit) or 3000001-
365535 (6 digit)
07-Read ExceptionStatus
484 and 584/984 Mode
n/a
MRX Master Memory Address Ranges
Operand Data Type
DL260 Range
Inputs X
0-1777
Outputs Y
0-1777
Control Relays C
0-3777
Stage Bits S
0-1777
Timer Bits T
0-377
Counter Bits CT
0-377
Special Relays SP
0-777
V-memory V
all (see page 3-56)
Global Inputs GX
0-3777
Global Outputs GY
0-3777
