User Manual
3-10 Operating Characteristics
3.2.1.2 Control States
The variable CONTROLSTATE (VID 28) represents the current control state, and will be one of the
values listed in Table 3-6.
Table 3-6 Control State Values
Value Description
Off-Line/EQUIPMENT OFF-
LINE
The Operator has put the Equipment off-line. In this state, only the
Operator can put the Equipment on-line. 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.
Off-Line/HOST OFF-LINE While in this state, the Equipment 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 cannot 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.
Off-Line/ATTEMPT ON-LINE The Operator has requested that the Equipment go On-Line,
causing the transition to this state. The Equipment sends a single
S1F1, indicating its desire to go on-line. When either a transmission
failure (T3 or RTY errors) occurs or a successful reply to the S1F1
has been received, a transmission is made out of this state.
On-Line/LOCAL The local Operator has control of the Equipment. 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 3.7 Remote Commands
or 4.2.41 S2F42 - Remote Command Acknowledge 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.
On-Line/REMOTE The remote Host Computer has control of the Equipment using
S2F41 (Remote Command). For details refer to 3.7 Remote
Commands.
The Operator may issue the PAUSE, STOP, and ABORT
commands while in Remote state. These commands will generate
an OperatorCommand event (CEID 4) as well as other messages
attached to these activities. Refer to Appendix B for further detail.