Page 7
Display time for each channel is programmable from 1-999 seconds (16.65 min.). This is useful for adjusting display time
to a rate which is consistent with the type of process being monitored. Scan time for each channel is independent of
display time. This permits programming long display times without losing track of the process on other channels.
The display can also be put in a hold mode by pushing the SCN/HLD key. When
this key is pushed, the display will briefly show 'HOLd' after which the display
will stop on the channel it was indicating. Putting the unit in HOLD mode inhibits
automatic display scanning and shows only one particular channel. While the
display is held on one channel, internally all the enabled channels are continuously
scanned for rate, difference, limits and other parameters. Also, during HOLD
mode the unit will periodically flash the display 'Cx HOLd' ( x=channel # on
hold) to indicate the status of the display mode. If an attempt is made to hold on a
channel that has been turned off then the unit will indicate so by displaying in the
format 'CHx OFF' ( x=channel # off).
To select another channel for display during hold mode, push the CH. SEL key. Each push will increment the channel
number. The display will first show the channel number (e.g. 'CHANEL 2' for channel # 2) followed by the process
variable in the form '0.123 PSI'. When channel selection is initiated using the CH. SEL key, the unit starts with
channel #1 and steps thru to channel #7 with each push of the key.
To take the unit out of HOLD mode and back into SCAN mode, push the SCN/HLD key. The display will briefly show
'SCAN' and then start scanning the channels.
DPS3000 Series compares all the channels against each other and constantly
tracks the channel with the highest and lowest process value. On push of a key,
the channel number and the value of process variable can be displayed. Also,
during SYS Setup, the unit can be programmed so that instead of scanning all the
channels it will only display the channel with highest or lowest process variable.
As the process changes, the display automatically switches over to the channel
with the highest (or lowest, if so programmed) reading. This is a very useful
function for applications involving multi-point monitoring of temperature in a
single process. For example, this feature can be used to find hot spots in a kiln.
During high or low channel scan mode the display will periodically flash 'HI CHAN' or 'LO CHAN' (depending upon
the selected mode) to indicate the status of the display mode.
To display high and low channel from any other display mode simply push the HI/LO key. Pushing this key once will
first display 'HI CHAN' and then the channel number and the process value will be displayed in the format 'C2 1234'.
The second push on the HI/LO key will first show 'LO CHAN' in the display window, and then the channel with the
lowest process value will be displayed.
NOTE: (i) The second push, to display low channel, must be initiated before the display reverts back to the normal
display mode.
(ii) If a channel is selected using the CH. SEL key prior to the push on the HI/LO key, then instead of
displaying high and low channels, the unit will display high and low peaks of the active channel.
Therefore, if it is desired to display high and low channels and not the peaks, do not select a channel
before pushing the HI/LO key.
In deviation display mode, DPS3000 Series will show the differential between a pre-programmed setpoint and process
variable being monitored on each channel by the scanner. Setpoint is programmed during CH Setup and can be any value
over the range of selected scale or thermocouple being used.
Types of Deviation Displays
There are two different ways of displaying channel devi a tion from their setpoint values: