Toshiba LF600F - Manual (Page 77)

TOSHIBA i6,F,8A0,8,6,9,
8.2.13 Span (range)
You can set the following constants in this setting item:
(1) Range type
(2) Unit of span (can be changed only in range 1)
(3) Span
(4) Hysteresis
• Range type
You can use multiple ranges by selecting range type. You can select a single range, multiple
ranges, or forward/reverse multi-ranges. Select one from five types shown below:
Range type Description
SINGLE Single range
4F-0R Unidirectional flow, automatic selection of multiple ranges by internal signal
2F-2R Bidirectional flows, automatic selection of multiple ranges by internal signal
EXT.2F-0R Unidirectional flow, multiple ranges selected by external signal
EXT.2F-2R Bidirectional flows, multiple ranges selected by external signal
Span (range)
■ Span can be set for flow velocity and flow rates:
;
(1) Setting range
Valid range of span is 0.3 m/s to 10 m/s in terms of flow velocity.
If you try to set the span outside of this range, one of the following messages appears:
* HIGH OVER SPEC, (if the set value exceeds 10 m/s)
* LOW OVER SPEC, (if the set value is less than 0.3 m/s)
Try again to set the span within the specified range.
(2) Limitation of multiple ranges
When multiple ranges are used, the following must be observed:
• Range 1 > Range 2 > Range 3 > Range 4 (unidirectional flow, multiple ranges)
• Range 1 > Range 2, Range 3 > Range 4 (bidirectional flows, multiple ranges)
If you try to set the ranges not conforming to the above, the following message appears:
* MULTI RANGE EROR *
Try again to set the ranges as specified above.
(3) Influence on Totalization counting rate (pulse rate)
If you have changed the span while the counting rate is set for totalization (pulse rate), the
counting rate for 100% output may have exceeded the maximum counting capacity.
In this kind of event, the following message appears and the system goes to the counting rate
setting sequence after all ranges are set.
* H. OVER CNT RATE or
* L. OVER CNT RATE
Set the counting rate (pulse rate) in accordance with 8.2.21 “Counting Rate (pulse rate)
and Pulse Width” for the newly set span.
-
76
-