C • TTL and Relay Control
Doc. 155028-01 08/20
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C.3
Configuring Relay Output 1 or 2 to Respond to the
Pump Flow
Follow the steps below to configure relay output 1 or 2 to open when the pump
flow stops and close when the pump flow starts. The relay output can then be used
to turn a connected device off and on with the pump flow.
1. Open the Chromeleon Instrument Configuration Manager.
2. In the Dionex Easion Properties dialog box, click the
State Devices
tab.
3. Select the relay output name (
Pump_ECD_Relay_1
or
Pump_ECD_
Relay_2
) and press the
F2
key. The Device Configuration dialog box appears.
4. Select the
Flow
Zero
check box.
To use the selected relay output for a different function, clear the
Flow
Zero
check box. Chromeleon will then control the relay output (see
5. Click
OK
.
C.4
Controlling TTL and Relay Outputs
The Dionex Easion provides two TTL outputs and two relay contacts for control
of functions in external devices (for example, a Dionex AS-DV).
The TTL outputs are normally at 5 volts. Setting a TTL output to 0 volts turns on
the action in the connected device.
The relay outputs can be used to switch any low-voltage control. Switched current
must be less than 200 mA and 60 V peak blocking. The relay-contact closures are
normally open; when the relay is closed, current flows to the connected device.
You can control the TTL and relay output states either by issuing direct control
commands or by including commands in an instrument method.
To directly control TTL and relay outputs:
1. In Chromeleon, press the
F8
key to open the Command window.
Relay loads in excess of 200 mA or with included power supplies over
60 V may damage the relay drivers on the CPU.
