Campbell Scientific TD Operating System Addendum for CR510, CR10X, and CR23X - Manual (Page 49)

Section 12. Program Control Instructions
12-5
PakBus Communication
The unique address for the datalogger in the PakBus network that will be
communicated with using this instruction.
The Pakbus address is set in the datalogger's *D15 mode.
Modbus Communication
The unique address for the datalogger in a Modbus network that will be
communicated with using this instruction (the slave device).
The Modbus address is set in the datalogger's *D8 mode. The valid range of
IDs for a Modbus slave device are 1 - 99. Setting the datalogger's Modbus
address to 0 disables it as a Modbus slave.
Command
This parameter determines what type of communication should take place in
the PakBus or Modbus network when the instruction is executed.
Command Description
1 Read Coil Status (Modbus command)
2 Read Input Status (Modbus command)
3 Read Holding Registers (Modbus command)
4 Read Input Registers (Modbus command)
5 Force Single Coil (Modbus command)
15 Force Multiple Coils (Modbus command)
16 Preset Multiple Registers (Modbus command)
21 Receive input location data from another datalogger (Pakbus
command)
22 Send input location data to another datalogger (Pakbus
command)
26 Get Value
27 Set Value
61 Read Coil Status (Modbus command)
62 Read Input Status (Modbus command)
63 Read Holding Registers (Modbus command)
64 Read Input Registers (Modbus command)
65 Force Single Coil (Modbus command)
66 Force Multiple Coils (Modbus command)
67 Preset Multiple Registers (Modbus command)
Notes:
Codes 61 through 67 are used when the Modbus packet will ride on top of
Pakbus as a datagram.
If Get Value or Set Value is used (26 or 27), parameter 5 is left blank and
Instruction 63 or 68 is used following this instruction to enter the variable
name in the datalogger's Public (or input locations) table that will be accessed.
If this parameter is indexed, the datalogger will proceed to the next instruction
only after it receives a valid response or error from the remote. Otherwise, the
PakBus command is queued, the datalogger proceeds to the next instruction,
and the communications are handled later when the remote replies. It may be