Functions And Settings - Hameg Instruments Ieee-488 Installationsanleitung

f u n c t i o n s a n d s e t t i n g s
3

functions and settings

3.1 flow control (SH1, aH1)
The flow control is for both transmitter and receiver (SH = Sour-
ce Handshake / AH = Acceptor Handshake) is required for all
further functions incl. the transmission of bus specific control
data and therefore supported. Extended flow control with the
possibility of a simplified indication is not implemented.
3.2 transmission and reception of data (t6, L4)
The instrument is able to transmit and receive data if the corres-
ponding function (T = Talker / l = listener) has been activated
by the control device. For addressing of both functions the same
primary basic address has to be used. Secondary addresses
are not supported.
The modes TAlK ONly and lISTEN ONly cannot be activated.
3.3 State information (Sr1, PP1)
Interface state information can be polled in sequential mode
(Serial Poll) as well as simultaneously from several devices
(PP = Parallel Poll) from the bus. All required interface set-
tings for parallel polling are made by the control device via the
IEEE488-Bus.
If the configuration of the device enable register is applicable
(note SCPI programming commands) the interface indicates the
control device internal state changes (Sr = Service request).
This avoids waiting time for the instrument's reply or the recur-
rent query for the instrument state. The required device settings
must be made each time the device is switched on.
3.4 communication initialisation (Dc1)
Bus specific control commands DCL (Device Clear) and SDC
(Selected Device Clear) will be processed by the internal ma-
nagement, independent of other SCPI commands still to be
processed (DC = Device Clear). Within the instrument the SCPI
command processing will be newly initiated, the execution of
current commands will be interrupted, and the data buffer will
be deleted. The flow control cannot indicate the acceptance for
new data transmission until these data have been completely
processed.
3.5 not supported functions (rL0, Dt0, c0, cf0)
The following functions are not supported:
– Switch over between local and remote with the opportunity
to lock local controls (rl = remote local)
– External start of the instruments basic functions (DT =
Device Trigger)
– Bus controller operation (C = Controller)
– Considering the control device IEEE-488 bus cable length
(CF = Configuration)
– local controls can be locked by SCPI commands (note SCPI
programming commands).
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Änderungen vorbehalten
3.6 Bus driver (E1)
The IEEE-488 bus data and control lines are controlled by drivers
with open collector outputs. As to be seen in IEEE-488.1 stan-
dard, this enables a data rate of up to 250000 Bytes per second.
3.7 addressing of IEEE-488 devices
The IEEE-488 standard specifies the address structure for
transmitter and receiver functions of a device. It allows you to
assign separate addresses for different device functions such
as transmission and receiving functions or for several different
transmission and receiving functions as appropriate.
These addresses can consist of a primary and a secondary part.
Both have a variable part (5 bit) for the real address and a fixed
group allocation (2 bit). The 8th bit is not used.
Thus instrument addresses in the range from 0 to 30 (00h to
1Eh) are available. The address 31 (1Fh) has a special function.
It is used to deactivate the function of an addressed group on
the bus (uNl = unlisten / uNT = untalk).
The following address groups are specified:
– Primary addresses for receiver function (coding: 20h)
– Primary addresses for transmitter function (coding: 40h)
– Secondary addresses (coding: 60h).
E.g. the complete primary address of the receiver function of a
device with the basic address 8 will be 40 (28h).
3.8 Selection of Primary address
combiScopes
The selection of an address is only possible if, as described
under Chap. 1.3: Firmware CombiScope a firmware version
05.105-yy.yyy or higher is present in the scope and the interface
HO740 is fitted.
Pressing the SETTINGS pushbutton calls the SETTINGS menu.
The function key INTErFACE opens the submenu SETTINGS
INTErFACE, which displays IEEE-488 and highlights ADDrESS
x. The address (x) can be selected from 0 to 30 by turning the
INTENS knob. It is important to ensure that this address is not
used by any other device on the bus.
Other devices
After pressing the SETuP resp. MENu button and the menu
INTErFACE the interface menu is displayed. The interface IEEE
488 is already selected. With the menu PArAMETEr (resp. SET-
TINGS with HMP series) the GPIB adress can be selected from 0
to 30 with the knob (HMO series with the knob in the CurSOr/
MENu area) on the front panel. It is important to ensure that
this address is not used by any other device.