Fluke 2620A User Manual

Page of 197
Using the Computer Interface
Using the IEEE-488 Interface
4
4-9
RS-232 Prompts
The instrument parses and executes, in turn, each command received from the host over
the RS-232 interface. The instrument returns one of the following three response
prompts to indicate the results of command execution:
=> No errors; the command was successfully parsed and executed.
?> The command was not understood. Used when an IEEE-488.2 Command Error or
Query Error was generated by the command.
!> The command was successfully parsed but could not be executed for some reason.
Used when an IEEE-488.2 Execution Error or Device Dependent Error was
generated for the command. An example of this would be trying to execute a
calibration command when calibration mode is not enabled.
Sample Program Using the RS-232 Computer Interface
Figure 4-2 presents a sample program for controlling the instrument over the RS-232
interface. This program is written in BASIC and is compatible with IBM PC, PC/AT, or
equivalent personal computers.
Using the IEEE-488 Interface
IEEE-488 Operating Limitations
The following limitations govern the IEEE-488 interface:
 
A maximum of 15 devices can be connected to a single IEEE-488 bus system.
 
The maximum length of an IEEE-488 cable used in one IEEE-488 system must be
the lesser of 20 meters or 2 meters times the number of devices in the system.
With an IEEE-488 interface installed and active, the instrument (2620A/05 or Hydra
Series II with 2620A-05K) supports the IEEE-488 capabilities shown in Table 4-2.
Installing the IEEE-488 Interface
The following instructions pertain to the 2620A/05 Data Acquisition Unit or a Hydra
Series II Data Acquisition Unit equipped with a 2620A-05K IEEE-488 kit. A standard
IEEE-488 cable attaches to the instrument rear panel. The following cables are available
from Fluke: Y8021 (1-meter), Y8022 (2-meter), and Y8023 (4-meter).
Select COMM (
K L) to check the interface setting. If "IEEE" is displayed, the
IEEE-488 interface is already installed and selected. If a numeric baud rate appears in
the left display, the RS-232 interface is selected; press 
D so that "IEEE" is displayed,
then press 
EE, select the address, and press EE again.