8
Streaming Mode (RS-485 units do not have streaming mode)
In Streaming Mode, a device will automacally output the data stream at a pre-
determined rate. The default rate is set to 50 ms. Only one unit on a given COM
port may be in streaming mode at a me.
To change a unit from Polling Mode to Streaming Mode, type (unit
ID)@=@<CR>. This is equivalent to changing the unit ID to “@”. If data does
not appear, check all the connecons and COM port sengs.
When sending a command to a unit in streaming mode, the ow of informaon
will not stop while the user is typing; and the typed text may not be readable
depending on the terminal sengs. If the unit does not receive a valid
command, it will ignore it. If in doubt, simply perform another carriage return
and start again.
To change a unit from Streaming Mode to Polling Mode, type @@=(unit
ID)<CR>. If entered correctly, the data stream will stop and the device will
now be in polling mode.
Data Format
The data frame on the screen represents the current measurements in the
device in the units shown on the display. By default, pressure controllers are
congured to output three columns of data
All data is displayed in the “device units” selected on the unit. Devices come
standard with units of PSIA or PSIG, depending on the type of the device.
The rst column is the unit ID. This column will be excluded if the device is in
streaming mode. The next column is pressure, and the third column will display
setpoint.
For example, suppose a controller with unit ID A was ordered with units of inHgG
and currently has a setpoint value set to 50.42 inHgG. The data frame may read:
A +50.42 50.42
Unit ID Pressure Setpoint
EPC/EPCD-Series Pressure Controller Data Format
Addional columns, including status codes, may be present to the right of the
last column.
Sending a Setpoint via RS-232 / RS-485
EPC’s can be ordered in analog input mode or in RS-232/RS-485 input mode. If
you’ve ordered the EPC in RS-232/R-S485 input mode the following secon will
provide instrucons on sending a setpoint via RS-232/RS-485.
If you’ve ordered the EPC in analog input mode and wish to change over to
RS-232/RS-485 input mode, you must read and adjust register 20 in the 16
bit programming of your EPC. Please contact the factory for instrucons
on changing from Analog to RS-232/RS-485 input mode via RS-232/RS-485
adjustment.
To send a setpoint via RS-232 / RS-485:
Method 1: Setpoint may be set as a oang point number in serial
communicaon using the setpoint command (unit ID)S(oating
point number)<CR>. For example, AS4.54<CR> changes the setpoint for
unit “A” to 4.54 in the current device units.
Method 2: The setpoint can also be set in reference to a poron of the full
scale. Type (unit ID)(integer)<CR>. Values between 0 and 64000 are
acceptable, which correspond linearly to 0 and 100% full scale ow respecvely.
Once a setpoint is accepted, the data frame will be returned with the setpoint
column changed accordingly.
