Martel Electronics 3001 - Manual (Page 43)

When using the IEEE-488 remote control interface, there are two restrictions:
• A maximum of 15 devices can be connected in a single IEEE-488 bus system.
• The total length of IEEE-488 cables used in one IEEE-488 bus system is 2 meters
times the number of devices in the system, or 20 meters, whichever is less.
See section 8 for instructions on configuring the 3001 for IEEE-488 (GPIB) operation,
including selecting the interface and the bus address.
A typical IEEE-488 (GPIB) connection is shown in Figure 32. See section 2.5 for the
location of the IEEE-488 (GPIB) port on the rear panel of the 3001.
Figure 32 - IEEE-488 (GPIB) Remote Connection
9.4 Changing Between Local and Remote Operation
In addition to local mode (front panel operation) and remote, the 3001 can be placed into
a local lockout condition at any time by command of the controller. Combined, the local,
remote, and lockout conditions yield four possible operating states as follows.
a) Local State
The 3001 responds to local and remote commands. This is normal front panel
operation. All remote commands received by the 3001 are processed.
b) Local with Lockout State
Local with lockout is identical to local, except that the 3001 will go into the
remote with lockout state instead of the remote state when it receives a remote
command. This state can only be entered by sending the IEEE-488 command
GTL (Go To Local) when in the remote with lockout state.
c) Remote State
When the 3001 is placed in remote, either via a RS-232 REMOTE command, or
via the IEEE-488 asserting the REN line, it enters the remote state. The left end
of the top line of the display changes to: rem.
Front panel operation is disabled except for the LOCAL (0) key. Pressing the
LOCAL key, using RS-232 to send the LOCAL command, or IEEE-488 to send
the GTL (Go To Local) message, returns the 3001 to the local state.
d) Remote with Lockout State
When the 3001 is placed in lockout, either via a RS-232 LOCKOUT command,
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