User Manual

Introduction 1-15
1.11 Machine Operation and the GEM Interface
1.11.1 Connecting to the Host
Fluidmove loads the GEM communications driver immediately upon startup. Once connection to the
driver is established, the device enters its default communication state as set by the Operator. This default
state can be set via the SECS/GEM Setup dialog box in Fluidmove. The recommended selection is
“Enabled”. If enabled, the Communications State Machine in the GEM driver sends the Establish
Communications Request message (S1F13) every ESTABLISHCOMMUNICATIONSTIMER seconds
until a reply is received from the Host. The Communication State changes to reflect this response.
Unlike other state machines, transitions in this state machine do not produce events or message reports to
the Host.
In the Main Window of Fluidmove, the GEM Status control can be seen in the lower part of the screen in
a status bar display format. The COMM section displays the GEM communication state of the program.
The CTRL section displays the control state of the program. The SPOOL section displays the spooling
state of the program. General GEM controls are available to the user by clicking on the SECS/GEM
button from the main window.
The initial (default) control state is set through Fluidmove’s SECS/GEM Setup dialog box.
“ONLINE/REMOTE” is recommended for this setting. This way, the Host has control of the machine
once the application has started and communication has been established. Refer to 1.11.7 SECS/GEM
Setup Dialog Box in Fluidmove for further details.
Normally, communications are established without fault, and going to the GEM setup dialog would only
be used by the Operator to manually go off line for maintenance reasons.
1.11.2 Device Identification
The Host periodically sends the Are You There message (S1F1) to the Equipment. If the communication
link is operational the Equipment automatically responds with the acknowledgment message (S1F2)
which contains Fluidmove model type (MDLN) and software revision number (SOFTREV). The Host
may receive more detailed information by requesting the MachineID variable from the Equipment.
1.11.3 Clock
The Host updates the GEM TIME structure periodically using the Date and Time Send message (S2F31).
Fluidmove will update its system clock to reflect the data presented by the Host. Current values of the
system time are used extensively in event logging and will be required to synchronize with comparable
events logged by the Host.