Avtech AV-1011-C-OP1 Instructions Manual page 22

OP-1 Operating Instructions
4.0 Changing the Unit GPIB Address
Since the GPIB data bus address for the pulse generator has been preset to "8" in
the factory, commands are required to be sent to this address. However, the user may
wish to change the address to any address in the allowed range of 0 to 30. This address
may be easily changed by re-setting the GPIB address switch on the GPIB Interface board
located inside the pulse generator chassis.
The address is set by means of a five position "Dipswitch " located on the top of a
small circuit card located inside the enclosure near the top rear. The switch may observed
to be set to the default address by noting that the Dipswitch position 4 is set in the OFF
position, defining a binary address of 8.
The switch setting is calculated as the sum of the switch weights in the OFF
position, calculated as follows: (a switch in the ON position it has a weight of zero):
Switch Number OFF Weight
1 1
2 2
3 4
4 8
5 16
For example, a switch with positions 1, 4 and 5 set to OFF will result in an address
setting of 25 (16 plus 8 plus 1 = 25).
5.0 Trouble-Shooting Aid
In the event that difficulties are encountered communicating via the GPIB
interface, two auxiliary communications status indicators have been included on the GPIB
interface circuit card. These status indicators are small LED lamps, one which flashes
briefly whenever a properly addressed command is received. The second LED will light
whenever an out-of-range value or invalid command is received, and will remain lit until a
valid command with a valid in-range value is subsequently received.
2/8/96 4 AN-101-1011