Measurement Computing TempScan/1100 - Manual (Page 115)

TempScan / MultiScan User's Manual 889897 System Operation 5-25
• Line 1: Configure the
ESR
Bit 5 (or
ESB
) in the
STB
to be set when a Device Dependent Error occurs.
• Line 2: Configure the Service Request (
SRQ
) when the
ESB
in the
STB
occurs.
Now the TempScan/1100 or MultiScan/1200 unit is configured so that when any Device Dependent Error
occurs, the unit will issue a Service Request (
SRQ
) to the controller. When the
SRQ
occurs, the controller
may perform the following sequence to determine the exact cause of the Service Request.
• Line 3: Query the
ESC
to determine the cause of the error.
• Line 4: Get the response.
• Line 5: The screen will show a Calibration Error (Bit 3 value = 2^3 =
008
).
• Line 6: Now, query the
CSR
to determine the specific cause of the Calibration Error.
• Line 7: Get the response.
• Line 8: The screen will show a Calibration Invalid Password Error (Bit 1 value = 2^1 =
002
).
• Line 9: Now, query the
ESR
. (Reading the
ESC
should have cleared it.)
• Line 10: Get the response.
• Line 11: The screen will show that the Device Dependent Error is no longer there.
• Line 12: Serial Poll the
STB
. The screen will show that the
ESB
in the
STB
is no longer set. Only
Ready Bit 2 is set. (Ready Bit 2 value = 2^2 =
004
).
Additional Operation
Trigger Latency
Each trigger source has an associated latency. This latency is the time between the actual Trigger (trigger
start event) and its recognition by the TempScan/1100 or MultiScan/1200 unit.
The following latency times are simplistic representations of the time between when the Trigger is detected
and when the Trigger has been processed. The hardware latency times, and the Interrupt Service Routine
(ISR) times to process other tasks during the trigger event but before its detection, are not accounted for. In
other words, these times may be offset as much as the hardware latency times, in addition to the process
time taken by the longest uninterrupted ISR.
Trigger Source & Latency
Type(s) Trigger Source Trigger Latency (Average) Observed Variation
1 @ character 2.255 ms 620.00 µs
2 GET (IEEE only) 645.6 µs 3.10 µs
3 TALK (IEEE only) 780.53 µs 12.00 µs
4,5 Selected Temperature Channel (Level) (See Note below) (See Note below)
6,7 External TTL (Rising or Falling) 610.95 µs 2.10 µs
8 Count (Post-Trigger) 45.9 µs 28.5 µs
9,10 Alarm (See Note below) (See Note below)
11 Absolute Time 44.5 µs 27.0 µs
Note: (1) When using a channel level or alarm as the trigger source, the trigger latency is dependent
on the number of channels. (2) With the TempScan/1100 unit, the maximum trigger latency is
the minimum scan time interval (as dictated by the maximum possible frequency) allowable
by the current configuration. (3) With the MultiScan/1200 unit, the maximum trigger latency
is the greater of the following time values: The programmed scan time interval, or the
minimum scan time interval (as dictated by the maximum possible frequency) allowable by
the current configuration.