41
Remote Operation
6 Remote Opera-
tion
6 .1 Interfaces
The instrument is programmable by a PC. Functions and
ranges can be selected and measurement values stored in
the instrument can be read out. The respective drivers are
available on the enclosed Product CD or can be downloa-
ded at http://www.hameg.com.
The Dual Interface USB/RS-232 HO820 and the GPIB in-
terface HO880 are electrically isolated from the measuring
circuit.
RS-232 Interface
Only three wire lines are connected inside:
❙pin 2 = Txd (transmit data)
❙pin 3 = Rxd (Receive data)
❙pin 5 = Gnd (Ground)
Electric voltage on Rxd must be according to the RS-232
hardware standard (+12/-12 V max). This provides the ca-
pability to communicate with any PC computer via a COM
port. The communication protocol is a Xon/Xoff proce-
dure. The command #X1 activates a software handshake.
Now, the transmission between PC and interface is not
synchronised via the hardware handshake and operates as
follows.
XON = 11h = transmission continue
XOFF = 13h = transmission hold
Once the instrument has received a command line (re-
fer to the definition below), it sends the Xoff character (19
dec). After all commands (in the received line) have been
computed and executed, it sends the Xon character (17
dec), making the transmission of a new line possible. Com-
mands are the same for all interfaces (For more details
concerning the optional interfaces refer to the correspon-
ding manual).
With the receipt of a remote command, the display shows:
The user may return to local mode by pressing the context
sensitive keys
5
below the LOCAL option (all other keys
are locked).
By sending the command LK1, the user may lock all keys
and in this case the display shows:
To establish a basic communication a serial cable (1:1) as
well as a terminal program like Windows HyperTerminal
is required. The Windows HyperTerminal program is part
of any Windows operating system. A detailed instruction
how to setup a basic communication using HyperTerminal
is available at the HAMEG Knowledge Base at http://www.
hameg.com/hyperterminal.
USB interface
You do not have to change the configuration. If required,
the baud rate can be changed. Connect the HM8135 with
your PC using a USB cable and install the USB drivers like
described in the manual of the USB interface HO820.
GPIB interface
Connect the HM8135 with your PC using a GPIB cable. It
is necessary to set the GPIB adress of the HM8135 to the
desired value. The adress is changed at the interface on the
rear panel. Do this settings only before starting the instru-
ment. It is not possible when the instrument is running.
6.2 Retrofit or change the interface
If you wish to change or retrofit the remote interface of
the HM8135, please follow the manual of the interface for
the installation and jumper settings. In addition to these in-
structions, you need to program the HM8135 in order to
activate the new interface. Please send one of the follow-
ing commands over the extra built in RS-232 interface:
Interface Command
USB (HO870/HO820)
813xcom2default:1
IEEE/GPIB (HO880)
813xcom2default:2
RS-232 (HO890)
813xcom2default:3
In order to deactivate all second interfaces please send:
813xcom2default:0
6 .3 Commands supported
General
There are two kinds of commands. The first one is the set
of old commands which are HM8133-2 compatible. They
are normally understood by the instrument without chan-
ging existing programs. The second one is a new set with
a similar syntax to the SCPI standard. We recommend to
use these commands which are the only one described
hereafter.
Commands are sent by lines to the instrument, one line
being a set of characters in ASCII code between 20 and
127 (dec), and terminated by an end of line terminator (10
dec) or 13 following by 10 (dec). Each line is composed of
one or several simple commands (elementary) separated
one another by the ”;” (semicolon) separator.
Example: :POWER 7 ; :FREQ 500E+6 ; :OUTP ON
The level is at +7 dBm, the frequency at 500 MHz and the
output signal ON. The strings of data are not case sensi-
tive. That means lower case and upper case are the same.
A simple command gives an access to a quantity or a
function of the instrument. All commands acting on the
Summary of Contents for HAMEG HM8135
Page 50: ...50 Flow Charts Flow Charts Function selection Step control Phi Phi Phi ...
Page 51: ...51 Flow Charts Amplitude Modulation Control FSK PSK GATE ...
Page 52: ...52 Flow Charts Phase Modulation Control FSK PSK GATE ...
Page 53: ...53 Flow Charts Frequency Modulation Control FSK PSK GATE ...
