Installation Of Ho88-2 And Ho89-2 - Hameg HM 8131-2 Manual

Option HO89-2 RS-232 interface
The interface HO89-2 is a full-duplex V24 interface with automatic
Baud rate recognition by a predefined start character (Space). The
operating system of this interface card features the following
commands:
*#VR Transmit version message
*#CR Transmit copyright message
#X1/0 XON-XOFF – protocol on/off
#BC Erase all input and output buffers
+#BD Activate newly defined Baud rate
+#W7 Select word length 7 bits
+#W8 Select word length 8 bits
+#S1 Select one stop bit
+#S2 Select two stop bits
+#PN No parity bit
+#PE Even parity
+#PO Odd parity
+#ST Transmit status
The commands designated with an asteric * deliver answers. The
formats are:
a) #VR HAMEG Ho89 version 1.0D 210290
b) #CR (c) 88/89 By MTE - Software X
c) #ST HM232 W(7/18) S(1/2) P(N/EO) X(1/0)
How to set the transmitting parameters
This is done with the aid of the commands marked with a plus
sign + . The interface will receive a command string at the end of
which must be the command #BD. This activates the commands
sent to the interface. After completion the Baud rate will be newly
determined by transmitting a space character.
Automatic Baud rate recognition
It is mandatory that the first character sent to the interface after
this was turned on or the command #BD was sent be a space
(20h). The interface then calculates the Baud rate and adapts
itself to that. Any other character or an incomplete character will
prevent the system from proper operation.
Functions if the programming DIP switches:
Number On Off
1 7 8
2 1 2
3 on off
4 even odd
5 CR CR+LF
XON/XOFF protocol
The command#X1 activates the software handshake. The
interchange between computer and interface will not be any
more be synchronized by the hardware handshake connections
but by two predefined commands.
XON = 11h = Continue transmission
XOFF = 13h = Stop transmission
Use of the HO89-2 requires a 25 conductor modem
cable. See the HO88-2 manual for further information.
Subject to change without notice
STOP
Function
Word length
Stop bits
Parity bit on/off
Even/odd parity
End of command string
8.0

Installation of HO88-2 and HO89-2

If the interfaces were ordered with the instrument they will be
factory installed. Later installation is possible. Upon installation
the pertinent safety regulations have to be observed. Disconnect
the mains plug before operning the instrument!
1. Opening of the instrument
Loosen the 9 screws on the rear panel. Now you can remove the
cover and the plastic rear panel. Then the housing can be
withdrawn towards the rear.
2. Removal of the installed interface
First loosen 2 more screws underneath the cutout for the interface
connector, then the interface card can be taken out after two flat
cables (4 and 8 conductors) were pulled off the connector CN2/
CN3.
3. Installation of the new interface
Before installing the new interface card make sure that the
underside faces upward. First connect the two flat cables which
can not be mixed up. The flat cables are connected to the
corresponding sockets on the card. The 6 conductor flat cable has
to fit in between the card and the shield. The 2 6 conductor flat
cables supplied with the HO88-2/HO89-2 (green, raster 2.5 mm)
are destined for the instrument types HM8122 and HM8142,
they are not required for the HM8131-2. Please watch for the DIP
switch. The card can now be fastened to the rear panel using the
2 M3 screws.
4. Reassembly
Slide the housing over the instrument and make sure that it fits
into the groove of the front panel. Remount the plastic rear panel
and the cover with the lettering and fasten both with the 9
screws.
Warning: Do not try an installation with the instrument
connected to the mains!
Interfacees
77