New Era NE-9000 Series Programmable Peristaltic - Manual (Page 57)

New Era Pump Systems Inc.
www.SyringePump.com
Model NE-9000
Publication #1200-04 49
A terminal emulator is available at, (www.syringepump.com/accessories.htm#software) for demonstration
purposes only, which allows more complex control of the pump. Also, this terminal emulator contains a
“Pump Programming Language” (PPL™), which allows Pumping Programs to be developed using
symbolic text, modified, and stored in computer files, then downloaded to the pump.
With a generic terminal emulator, setup the terminal emulator with the same baud rate as the pump and
with an 8 bit data, no parity, and 1 stop bit (8N1) data frame. Set the communications port to the port that
is attached to the pump. Also enable local echo (half-duplex) and turn flow control off.
From the terminal emulator, you can interactively control the pump by typing in commands on your
computer and seeing the pump’s responses on your screen. This will give you a feel for how the
commands work in addition to allowing you to quickly develop the control sequence that will eventually
be coded into the software being developed.
The final benefit of using a terminal emulator is the elimination of several variables if the control software
does not work properly. If the pump works correctly with the terminal emulator, then this verifies that the
hardware is working properly and will work with any software. Any communications problems can then
be narrowed down to the control software.
SyringePumpPro software provides licensed Windows GUI based control program for this pump.
Note on USB: If an RS-232 port is not available on your PC, the pump may be operated through a USB
to RS-232 cable (available as an accessory). The PC will create a virtual RS-232 communications port
that communicates through the USB to RS-232 cable. The terminal emulator can communicate through
this virtual port.
13. Logic Interface: TTL Input and Output
New Era Pum p Systems Inc.
www.SyringePump .com
Farmingdale, NY
Figure 2: Rear of Pump
On the rear of the pump is a DB-9 connector, below the ‘TTL-I/O’ label, which is used for TTL I/O. The
logic signals on this connector permit bi-directional control with external equipment.
Control input TTL logic levels must be held steady for a minimum of 100 ms to be recognized. To
minimize the possibility of false signals caused by glitches and ringing, which could be caused by the
closure of mechanical switches, TTL control inputs are software filtered. With a sampling period of 50
ms, glitches of less than 100 ms are filtered out.
Edge detection requires the detection of a change in TTL levels. With a minimum of 100 ms to detect a
level, an edge requires a minimum of 200 ms to be detected. Since the next level change can be detected
in 100 ms, creating another edge, the maximum edge to edge frequency is 10 Hz.
Edge changes to the ‘Pumping Direction’ and ‘Operational Trigger’ inputs must occur at least 50 ms apart.