Precision Digital PD6080 - Manual (Page 99)

PD6080/PD6081 Super Snooper Modbus Scanner Instruction Manual
99
SCANNER OPERATION
The PD6080/6081 scanner is capable of operating as a Modbus Master, Slave or Snooper. As a Slave,
the PD6080/6081 requires connection to a Master device: PLC, DCS, etc. As a Master, the PD6080/6081
interfaces up to sixteen slave devices and can alternately display their Process Variables. As a Snooper it
can be connected anywhere in the RS-485 bus to read any of the variables being requested by the
Master device.
Four math channels (C1-C4) are available to perform operations on any PV or math channel, with adder
and factor constants, and display the results. Engineering units or tags may be displayed with all PVs or
math channels. Another level of Math functions can be performed on the resultant math channel Math2.
For example, the operator can use the Math2 Channel to calculate the Sum of all other Math Channels,
which may have each performed a different Math function.
The dual-line display can be customized by the user. Typically the upper display is used to display the
PV, while the lower display is used to display the tag for each PV.
Additionally the scanner can be set up to display any input or math channel on the upper display and
alternate between tag & units on the lower display. The relays and analog output can be programmed to
operate based on any PV or math channel.
The scanner is capable of accepting two analog input channels (A and B) of either current (0-20 mA,
4-20 mA) or voltage signals (0-5 V, 1-5 V, 0-10 V,
± 10 V) and displaying these signals in engineering
units from -99999 to 999999 (e.g. a 4-20 mA signal could be displayed as -50.000 to 50.000). The analog
input channels must be mapped to PVs using the IDs 256-259.
Front Panel Buttons Operation
Button Symbol Description
Press to enter, exit Programming Mode, or exit max/min readings
Press to move to the previous PV or math channel
Press to move to the next PV or math channel
Press once to pause scanning, press again to resume scanning
Function Keys Operation
During operation, the programmable function keys operate according to the way they have been
programmed in the Advanced Features – User menu.
The table above shows the factory default settings for F1, F2, and F3.
F4 Operation
A digital input, F4, is standard on the scanner. This digital input is programmed identically to function keys
F1, F2, and F3. The input is triggered with a contact closure to COM, or with an active low signal. During
operation, F4 operates according to the way is has been programmed in the Advanced Features – User
menu. See page 91 for details.
Maximum/Minimum Readings
The max & min readings (peak & valley) reached by the PVs or math channels can be displayed by
assigning the display to max/min through the Display Setup menu.
A digital input should be programmed to reset the max & min readings.