DL8000 Preset Instruction Manual
Revised February-2016
Communications Protocols
D-3
This is a primary alarm and is not configurable. You can, however, set
the Port Timeout parameter to zero to disable the alarm for that port.
Parameters are:
COMM2
[63,0,152]
COMM3
[63,0,153]
COMM4
[63,0,154]
COMM5
[63,0,155]
Note
:
Use ROCLINK 800’s Comm Port screen (
ROC
>
Comm Ports
)
to specify the general settings of a serial port to define these
settings.
D.1.3 Supported Protocols
The TAS can communicate with a DL8000 using either the Modbus
protocol or the DanLoad 6000 protocol.
Modbus
Protocol
You can configure a DL8000 to use either Modbus RTU or ASCII
transmission modes, and either Most Significant Byte (MSB) or Least
Significant Byte (LSB) orders. Set these values using the Comm
Mode and Byte Order fields on the General tab of ROCLINK 800’s
Modbus Configuration screen (
Configure
>
MODBUS
>
Configuration
).
The Comm Mode option [117,x,0] controls the type of transmission
mode:
RTU
(Value=0) or
ASCII
(Value=1). The Byte Order option
[117,x,1] controls which byte is sent out first for floats, short integers,
and long integers. Valid values are
Least Significant Byte
First
(Value=0), associated with little-endian processors or Most Significant
Byte First (Value=1), associated with big-endian processors.
The Modbus protocol is a register-based protocol. You have to map
Modbus registers to the DL8000 TLP parameters. Refer to
Section D.4,
Mapping Modbus Registers
.
DanLoad 6000
Protocol
The DanLoad 6000 protocol is Modbus-compatible protocol, since it
uses Modbus RTU message framing. Modbus function codes for
normal queries and responses are 0x41 and 0x42 (hexadecimal). The
Modbus protocol reserves function codes 0x41 to 0x48 for user-
defined “custom functions.” Consequently, the DanLoad 6000
protocol is a
customized
Modbus protocol.
Under DanLoad 6000 protocol, the TAS system establishes
communication using a Start Communications command (hex value
0x21). This initializes the DanLoad 6000 alternating sequence function
code to the function code in the Start Communication command. The
operation at DanLoad 6000 remains unaffected by Start
Communications command (hex 0x21).