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6-3 ADAM-6000 Commands
ADAM-6000 and ADAM-5000/TCP system accept a command/response form with the host computer.
When systems are not transmitting they are in listen mode. The host issues a command to a system
with a specified address and waits a certain amount of time for the system to respond. If no response
arrives, a time-out aborts the sequence and returns control to the host. This chapter explains the
structure of the commands with Modbus/TCP protocol, and guides to use these command sets to
implement user's programs.
6-3-1 Command Structure
It is important to understand the encapsulation of a Modbus request or response carried on the
Modbus/TCP network. A complete command is consisted of command head and command body. The
command head is prefixed by six bytes and responded to pack Modbus format; the command body
defines target device and requested action. Following example will help you to realize this structure
quickly.
Example:
If you want to read the first two values of ADAM-6017 (address: 40001~40002), the request command
should be:
Figure 6-1 Request Comment Structure
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