Spirax Sarco VLM30 - Devices with Modbus Communication

IM-P736-02 EMM Issue 3
44
VLM30 In-Line Vortex Flowmeter
3.19 Devices with Modbus
®
communication
3.19.1 Terminals
Note: The Modbus protocol is an unsecured protocol, as such the intended application should be assessed
to ensure that these protocols are suitable before implementation.
Fig. 28 VLM30S Terminals
Terminal Function/comment
PWR + Power supply.
PWR -
A (+)
Modbus
®
interface RS485.
B (-)
DIGITAL OUTPUT 1+ Digital output, positive pole.
DIGITAL OUTPUT 2 Bridge after terminal 1+, NAMUR output deactivated.
DIGITAL OUTPUT 3 Bridge after terminal 4−, NAMUR output activated.
DIGITAL OUTPUT 4- Digital output, negative pole.