GE Mark VIe System Manual page 105

There are four types of GSM messages:
• Administrative
• Event-driven data
• Periodic data
• Command
Administration Messages are not associated with given Mark controller. These requests are messages from the DCS to the
GSM server to interrogate its capabilities.
Event Driven Messages are sent from the GSM server to the DCS in reaction to a system alarm or event occurring or clearing.
Event driven messages include:
• Process alarm is initiated or clears
• Internal control diagnostic alarm is initiated or clears
• Process event occurs
• Sequence of Event (SOE) contact input opens or closes
Periodic Data consists of variable sets transmitted from the GSM server to DCS either once or periodically (rates up to once
per second). This data is typically used to refresh DCS process display screens.
Command Requests fall into two classes:
• Process alarm command requests
• Process command requests, either a momentary contact push-button or a variable write command
Note For additional information, refer to the WorkstationST GSM 3.0 User Guide (GEH-6757) and the WorkstationST GSM
3.0 Application Guide (GEH-6760).
Communication Protocols
Public Information
GEH-6721_Vol_I_BP System Guide 105