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Gossen Metrawatt GmbH
5
Remote Programming Operation
SPL Series Electronic Load supports both local operation and remote control. The previous chapter has introduced how to use the
front panel keys and knobs to operate on the load. This chapter will introduce you to how to program the load from the remote control-
ler. The similarities between local and remote programming will become apparent as you read this chapter. The intent of this chapter is
to help users quickly become familiar with remote programming operations. Programming examples given in this chapter use the SCPI
commands in their simpliest form. Please refer to the “SPL SCPI Programming Guide” for detailed introduction of all SCPI commands.
5.1
Communication Interface
5.1.1
RS232
RS232 interface is standard. Use the cable shipped with the load to connect the load to a computer correctly. Select RS232 interface
in the MENU, and set the baud rate, parity, data bit, stop bit, and flow control parameters to be used. Set the same parameters in the
software on the computer, and input the right SCPI command to operate the load.
5.1.2
USB
USB interface is optional. It can be used only when the load has installed USB communication module and the relevant driver has been
installed on the computer. Use USB cable to connect the load to a computer correctly. Select the USB interface in the MENU and input
the right SCPI command to operate the load.
5.1.3
GPIB
GPIB interface is optional. It can be used only when the load has installed GPIB communication module and the relevant driver has
been installed on the computer. Use GPIB cable to connect the load to a computer correctly. Select the GPIB interface in the MENU,
and set GPIB address. Each instrument you connect to the GPIB interface has a unique address assigned to it. Input the right SCPI
command to operate the load.
5.2
Flow Control Selection
When RS232 interface is used, the flow control can be enabled or disabled. The load provides two options: ON and OFF. ON: enabling
the flow control; OFF: disabling the flow control. When “OFF” is selected for flow control, the lower baud rate should be set to ensure
normal communication.
5.3
Remote Control Indicator
There is a REM indicator on the front panel of the load. When the load receives the remote command (SYSTem:REMote) via RS232 or
GPIB interface, the REM annunnciator turns on. And the load enters remote control status. In this status, all operations on the load are
controlled by the remote controller; the front panel keypad and knob has no effect (except
key +
key). The REM remote con-
trol indicator turns off and the load returns to the local control after receiving the command to return to local control (e.g. SYS-
Tem:LOCal). Or you can return the load to local control from remote control by pressing the
key +
key.
5.4
Sending a Remote Command
You can use the computer to set operation mode and operation parameters remotely for the load.
5.5
Returning Data
The load can return the values of parameter settings, input voltage and current, as well as input power to computer. It can also return
information relating to the internal operation and module identification. For example: the query command ( “MEAS:CURR?”) asks the
load to return the actual current at the Input binding posts. Please refer to “SPL SCPI Programming Guide” for detailed information on
using query commands. The load stores the response to the query in an output buffer which will hold the information until it is read by
the computer or is replaced with new information.
5.6
Remote Programming Commands
The SCPI commands have many optional key words for the programmer. Getting familiar with those key words will help you to know
the programming better. Most of the commands have a query syntax which allows the present parameter settings to be returned to the
controller. Please refer to “SPL SCPI Programming Guide” for details. The load` s major functions can be programmed with a relatively
few number of these commands. The following points are important to remember when you are remotely programming CC, CR, CV,
and CP values.
5.6.1
Modes
The CC, CR, CV, and CP values can be programmed whether or not the associated mode is active. If the input is turned on, all of the
applicable values will take effect at the input when the associated mode is selected.
5.6.2
Transient Levels
The transient CC, CV, or CR level must be set to a higher level than the respective low level, or the transient operation will be disabled.
