5.11. STEM
®
protocol (RS232 & RS485).
Stem command SET can be operated using RS232 or RS485 links. Baud rate is
19200, N, 8, 1 for STEM protocol. RS-250D-250 has auto configuration for all
parameters concerning the STEM protocol.
Command set as follows: -
AS Set unit base address, applied after response
(0 to 99)
SE Stirrer enabled
(0 to 1)
SR Stir speed ramp rate (set rpm/time achieved – mins).
(1 to 10)
SS Stir Speed (RPM)
(400 to 2000)
TE Thermal control enabled
(0 to 1)
TT Target temperature. (ºC).
(0.0 to 153.9)
TR Temperature Ramp rate (ºC/min)
(0.0 to 5.0)
Note: For TR 0.0 indicates no control.
Query command set
QC Request commanded variables
QD Request debug variables
QF Request system principal fixed values.
QM Request measured data
Using a suitable terminal, type in and test some of the commands and query set,
STEM protocol.
Examples of STEM Command protocol used
.
“<CR>” Is a carriage return character.
Type in:
>40 SE1 #0000 <CR>
Response: <40.00 OK <CR>
Result:
Stirrer enabled (LED for stirrer ON< RS-250D-250 will commence stirring).
Type in:
>40 SE0 #0000 <CR>
Response: <40.00 OK <CR>
Result:
Stirrer disabled (LED for stirrer OFF, RS-250D-250 will stop stirring).
Type in:
>40 TT123,4 TE1 #0000
Response >40,00 OK <CR>
Result
Target temperature set to 123, 4ºC, thermal control enabled (LED for ON<
temperature will begin to raise block temperature).
Type in:
>40 SS2000 SE1 SR2 #0000 <CR>
Response: <40,00 OK <CR>
Result:
Stirring enabled, stirring speed set to 2000 rev/min, Stirrer ramp rate set to 2,
(Stirring speed will steadily increase to 2000 rev/ min over 2 minutes).
GSIOC is a different control command set used in conjunction with
Gilson branded handling systems.
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