Hach sc1000 - Manual (Page 120)

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Advanced Operations
6.4.1 Bus status
The Bus Status menu informs the user about communication problems which might
restrict data availability and degrade the overall sc1000 controller operation.
More detailed information can be obtained from the Diagnostic file (refer to section 6.3.9
on page 116 ).
TEST/MAINT
DISPLAY INFO
SOFTWARE VERSION Displays the software version of the display module
SERIAL NUMBER
Displays the serial number of the display module
TEST/MAINT
BUS STATUS
RESET COUNTER
Resets data acquisition and updates the START time.
Enters a sub menu where resetting can be confirmed/cancelled.
START
Displays a time stamp (date, time)
The time stamp indicates when data acquisition of the sc1000 controller was started/reset.
COMMUNICATION Communication Statistics
TIMEOUTS_3
Displays the event count when a device (probe or input/output module) does not respond to a
controller request within a guaranteed time.
The sc1000 controller tries to connect to the device three times. After the third unsuccessful try
the counter increases by 1. Generally, the counter increases, if bus devices/bus segments are
not properly connected or the bus devices encounter serious errors.
TELEGRAM_3
Displays the event count when the sc1000 controller detects a malformed response to a request.
The sc1000 controller tries to detect a valid response three times. After the third unsuccessful try
the counter increases by 1. Generally, the counter increases, if electromagnetic shielding is not
appropriate for rough environment.
TOKEN CIRCULATION
The Token Circulation duration displays the time where all master devices get the master role
(“token”) once.
In an sc1000 controller there can be multiple master devices, for example devices that put
requests to other bus devices (for example display unit, current output, relay, and network
adapter card). As only one master can be active, the master role is shared among these in a
certain “round robin” way.
The Token Circulation time influences the time, within output modules can detect value changes
from other devices, and therefore shows a sc1000 controller response time. This time depends
on the number of connected devices.
MAXIMUM Maximum TOKEN CIRCULATION duration in ms since START.
(at time) Time stamp when the MAXIMUM TOKEN CIRCULATION duration was measured.
AVERAGE Average TOKEN CIRCULATION duration in ms (taken for the last 128 round-trips).
MEDIAN
Median TOKEN CIRCULATION duration in ms (taken for the last 128 round-trips). This value is
not influenced by isolated/non repetitive events (for example log file transfers/software updates)
and is therefore more reliable than the AVERAGE value.