Flintec MCS-64 ModbusOnEthernet - Manual (Page 9)

Manual MCS-64: Modbus on Ethernet Page 9
4 M
ODBUS
M
APPING
The MBAP header “Unit Identifier” field is used to select a module in the backplane. Address 0
(zero) is reserved for broadcast. Address 1 to 64 is then used for direct communication with any
LDM in the backplane using registers in the range 2000-2FFF (hex). Access to the gateway
should use address 0xFF (255 dec) and registers in the range 3000-3FFF(hex).
Currently implemented function codes are: Access
03 Read Holding Registers
04 Read Input Registers
06 Write Single Register
16 Write Multiple Registers
Used exception codes are: Meaning
01 Illegal or unkown function code
02 Illegal data address or no response from LDM
4.1 Modbus Register Map Overview
Register Type Size Access Function
2000 – 2FFF Selected LDM
3000 – 30FF Gateway
4.1.1 Gateway Register Map
Register Type Size Access Function
3000 Int16 1 R/W LDM selector [0..63]
3001 Int16 1 R/W LDM multiple register selector.
3002 Int16 1 R/W LDM multiple register mode
3003 – 300F - - (reserved)
3005 Int16 1 R/W Auto-Scan Control/Status
Bit:
15 10 9 2 1
+------------+--------+-----+
| Last scan | unused | R/S |
+------------+--------+-----+
3006 Int16 1 R/W Auto-Scan Port (IP port no.)
3007 Int32 2 R/W Auto-Scan Interval (ms)
3009 – 30FF (reserved)
3100 – 31FF R/W Multiple register access across multiple LDM modules.
3200 – 32FF Float 2+2+1 R Multiple read of LDM packets
3300 – 33FF Integer 2+2+1 R Multiple read of LDM packets