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6270A External 24V Drivers (2271A, 8270A, 8370A also)

The below text and images are most of the External Drivers Section from the the 6270A Manual, pages 52 to 55. Note that the output of the drivers drops to about 12 volts shortly after activation, so the intended use of the external drivers is to drive 12V intermittent duty cycle solenoid valves. If you wish to use the external drivers to operate 12V valves, it is recommended to use with Fluke Calibration accessory valves like PK-VLV-ISO-40M or PK-VALVE-20M. 

The drivers can also be used to turn on a relay (that could be used to turn on a vacuum pump). However, the driver outputs are modulated so they will likely not function well with a relay, and the connected device will likely turn off although the driver is still activated.

There are two options to smooth the driver output to work with a 12 to 24V valve or relay that needs a continuous signal.

First option: This option allows use of the front panel to turn the drivers on or off. To smooth the modulation, a capacitor can be put across the driver contacts. One example would be a 4700 uF (micro Farad), 50V capacitor. Note that the use of this capacitor will keep its output active for up to 15 seconds after the driver is turned off. (Mouser Part# 647-LKS1V472MESZ)

Second option: This option requires sending a remote command to the pressure controller to set the duty cycle of the driver. The remote command is in the 6270A/8270A/8370A/2271A Programmer's Manual but is noted as only for use with 8270A/8370A. Since then, it also works with 6270A. The remote command is here:


The duty cycle would be set to 50 for a continuous 12V output.  The duty cycle option for a driver will remain until changed by remote command again. The setting will go back to default if a reset is done on the controller also. The duty cycle will remain if the controller is power-cycled. However, it is a good idea to send this remote command to the controller at the beginning of every test that will use a driver in this way. If you are using COMPASS for Pressure (or Flow) calibration software you could add a pre-test Test macro that sends this command to the active reference or set device. Contact pressure technical support at the link at the bottom of this page, or by email to for more information. 

The driver connector terminal plugs are included with Fluke Calibration accessories that use the external drivers (CPS, isolation valve) and are available separately in two or four-position models. Prices are available by contacting Fluke Calibration at or by calling +1.877.355.3225

Part Number: 4578746 
Manufacturer / Part Number: Phoenix Contact 1840366

Part Number: 4579040
Manufacturer / Part Number: Phoenix Contact 1840382

External Driver Communication
The Product has four external 24 V dc powered drivers. These drivers support several optional accessories and can support the driving of solenoids for customized solutions. The driver status can be set with the display and remote interfaces. Each driver is a low-side switched 24 V dc component. Each Channel includes a PTC-type resettable fuse. Maximum continuous power per channel is 10 W and total continuous power maximum for all 4 channels combined is 24 W.

Configure the Driver
Turn the CPS and/or isolation valve accessories on from the Instrument Setup menu (Setup>Instrument Setup). Both require the correct pneumatic connections and electrical connections. Touch the External 24V tab to see or set the state of the external drivers. Touch the Isolation Valve tab to set up the isolation valve.
Drivers are identified in the External 24V menu and on the rear panel of the Product as DRV1, DRV2, DRV3, DRV4 (see Figure 15). Each solenoid uses two wires, one wire goes into each connector.
• DRV1 uses the two top left inputs
• DRV2 uses the two top right inputs
• DRV3 uses the two bottom left inputs
• DRV4 uses the two bottom right inputs

Several of the drivers support specific accessories such as the CPS and Isolation valve for system stacking.
• DRV1: CPS Valve
• DRV2: CPS Valve
• DRV3: External Isolation Valve
• DRV4: Auxiliary

Note that with main firmware version 1.0 and higher Drivers 3 and 4 have changed.
• DRV1: CPS Valve
• DRV2: CPS Valve
• DRV4: External Isolation Valve

See the associated appendices for additional information on these accessories.
The External 24 V menu (Setup>Instrument Setup>External 24V) also shows the driver states for any auxiliary chassis when working in a system with multiple chassis.

In these primary functions, the solenoid drive is modulated to reduce power consumption during continuous use.

The external drivers of the 2271A and 8270A and 8370A pressure controllers operate the same way but the DRV numbers may not correspond to the same accessories.

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