Manual

Operating Characteristics 3-11
3.2.1.2 Control States
The variable CONTROLSTATE (VID 4) represents the current control state, and
will be one of the following values:
3.2.1.2.1 Off-Line/EQUIPMENT OFF-LINE
The Operator has put the GES-1993 Off-Line. In this state, the Host may not put the
Equipment On-Line, only the operator can attempt this from this state. Any Host-
initiated primary message (except S1F13 and S1F17) will be replied to with an SnF0
ABORT message by the Equipment. The Equipment will not send any primary
messages except for S1F13 when necessary to establish communications, and the
S9F1 and S9F9 messages for SECS errors.
3.2.1.2.2 Off-Line/HOST OFF-LINE
While in this state, the GES-1993 will accept either the S1F17 (Go Online), or the
S1F13 (Connect Request) message. When in this state, the operator has allowed the
Host to put the Equipment On-Line, but the Host has not yet done so, or the Host has
just put the Equipment Off-Line by sending S1F15. The Host may request for the
Equipment to come On-Line by sending the S1F17 Go Online message. The
Operator can not put the Equipment On-Line from this state.
The S1F13/S1F14 messages are used to maintain the Communications Finite State
Machine. All messages (except S1F13 and S1F17) received will be replied to with
the SnF0 ABORT message. The Equipment will not send any primary messages
except for S1F13 when necessary to establish communications, and the S9F1 and
S9F9 messages for SECS errors.
3.2.1.2.3 Off-Line/ATTEMPT ON-LINE
The Operator has requested that the Equipment go On-Line, causing the transition to
this state. GES-1993 sends a single S1F1, indicating its desire to go On-Line. When
either a transmission failure (here, T3 or RTY errors) occurs, or a successful reply to
the S1F1 has been received, a transmission is made out of this state.
3.2.1.2.4 On-Line/LOCAL
The local operator has control of the GES-1993. The Host can send S2F41 (Remote
Command), but the Equipment will reject it with 0x40 return code. The REMOTE
command sent by the Host will not be rejected by the Equipment. See "S2F42 -
Remote Command Acknowledge" or "Remote Commands" for details.
In LOCAL mode, the Equipment continues to send event and alarm reports to the
Host. The Host can monitor operations, but cannot control processing. However,
the Host can still exert "controls" other than S2F41 which do not directly affect
processing. For example, the Host can enable/disable alarms and set the clock.