Delta RMC101 User Manual
Page 501
Serial (RS-232/422/485) 5.5
Communications
5-251
• 03: Read Holding Registers
• 06: Preset Single Register
• 16 (10 Hex): Preset Multiple Registers
• 23 (17 Hex): Read/Write 4X Registers
Each of the above functions acts on 4X or Holding registers. The RMC has these 4X registers
mapped as described in the following topic:
• RMC Register Map (Modbus/TCP)
Protocol-Specific Settings
The RMC Modbus/RTU implementation has one protocol-specific setting: the node address.
Enter this address in the Serial Module Options dialog box, as described in Configuring the
RMC SERIAL.
5.5.3.2 Using DF1 (Full- and Half-Duplex) with the RMC SERIAL
Note:
Full- and half-duplex DF1 was added to the RMC SERIAL module in 20010627 firmware.
Modules with firmware dating prior to this do not support DF1.
The DF1 Protocol
Allen-Bradley’s DF1 Protocol and Command Set Reference Manual (pub. no. 1770-6.5.16) is the
authority on the DF1 full- and half-duplex protocols. This manual is available on Allen-Bradley’s
web site (http://www.ab.com). As of this writing, the following URL contains this document:
http://www.ab.com/manuals/cn/17706516.pdf. When this link is out-of-date, try searching for the
above publication number.
Full-duplex DF1 is used for peer-to-peer communication. Therefore, only two devices can
communicate with one another. Only RS-232 or RS-422 support full-duplex.
Half-duplex DF1 is used for master-slave communication with one or more slaves. When more
than two devices communicate with one another, 2-wire RS-485 is used. Otherwise, any line
driver can be used.
RMC Support for DF1
Both full- and half-duplex DF1 use the same application protocol, which consists of commands
and functions for the slave or peer to execute. The RMC supports the following DF1 functions:
• PLC5 Word Range Write (CMD=0x0F, FNC=0x00)
• PLC5 Word Range Read (CMD=0x0F, FNC=0x01)
• PLC5 Typed Write (CMD=0x0F, FNC=0x67)
• PLC5 Typed Read (CMD=0x0F, FNC=0x68)
• SLC Protected Typed Write with 2 Address Fields (CMD=0x0F, FNC=0xA9)
• SLC Protected Typed Read with 2 Address Fields (CMD=0x0F, FNC=0xA1)