3-20
3
WF? reg, num
Write Floating Point Value Command (0x16). Writes
an IEEE 754 single precision 32-bit value to two
registers in low word to high word order. reg speci-
fies the low word. reg +1 is the high word. num is
determined by the parameter being controlled and
can range from 2
127
to 2
-127
D time
Timeout Command. Sets timeout value of Modbus
response message in milliseconds. Timeout is the
total time for the message to be received by the
80x9. Value for
time
is 1 to 65,535 milliseconds. A
value of 0 disables the timeout. The default value
is 300 ms. Caution - Do not use 0 or values that
exceed the Network timeout which is normally 3 to
10 seconds.
D?
Queries the current timeout setting.
E?
Read Error Command. Reads and clears the Modbus
Error Register and bit 6 in the Event Status Register.
Returns a error code whose value is 0 to 255. Current
error values are:
0
No errors present
1
Exception Code 1
2
Exception Code 2
3
Exception Code 3
100 CRC Error
101 Timeout Error indicates no characters
received in the response message.
2nn Partial or corrupted message received.
where nn is the number of received bytes.
Notes:
1. All values are in decimal. To enter HEX values, the value must be preceded with
a #h . i.e. 100 decimal = #h64
2. Response parameter format set by SCPI FORMat command. Default is ASCii
3.
Do not combine the Modbus commands in Table 3-5 with IEEE-488.2
commands or SCPI commands to avoid query errors or otherwise confusing the
GPIB<->Modbus Interfaces.
4.
The [?] is an optional symbol for smart programs like ICS’s GPIBKybd program.
These programs can recognize the command as a query and automatically read the
response
.
TABLE 3-5 MODBUS COMMANDS CONT'D
Syntax
Meaning
