Chapter 6 – Communications
Page 64
TestEquity 101H Temperature/Humidity Chamber
Programming Syntax for the F4T Controller
The following applies if the F4T serial interface is configured for Data Map 1.
This only applies
for programming through the GPIB or Ethernet Modbus converters.
The F4T Controller uses two consecutive register to control a value or to read back a process
variable. The two registers hold an IEEE-754 32-bit floating point word. The registers are read
and written to in the low word-upper word order. The RF? query reads a 32-bit floating point
value from two sequential register in low word-upper word order. The RF? does not require the
number of registers to read since it is fixed at two registers.
Some registers in the F4T Controller are 16-bit words.
Modbus Register Read / Write Commands
The RF command reads the num value in floating point format to two consecutive registers
starting with the low word register. Use this to read 32-bit floating point registers.
RF?
reg
Read 32-bit floating point register command
The R command reads the numeric value in one register. Use this to read 16-bit registers.
R?
reg, 1
Read 16-bit register command
The WF command writes the num value in floating point format to two consecutive registers
starting with the low word register.
WF
reg, data
Write register command
Reg = Modbus register plus next consecutive register
Data = ASCII data written as a direct numerical value
Examples:
Write Temperature Set Point
WF 2782, value
Read Chamber Temperature
RF? 27586
Read Closed Loop Set Point
RF? 2810 (instantaneous temperature set point during a ramp
or profile)
Turn (Event 1) ON
W 16594, 63
Event 1 is “Power”
Turn (Event 1) OFF
W 16594, 62
