Brooks Instrument SLAMf Series - Manual (Page 15)

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Section 1 - Introduction Installation and Operation Manual
X-TMF-SLAMf-MFC-eng
Part Number: 541B032AAG
April, 2013
Brooks ® Digital MFC's and MFM's
RS-485 Communications
The Brooks SLAMf Digital Series is equipped with RS-485 communication
capability. This form of multi-drop capable communication provides access
to many of the Brooks Smart II Digital Series functions for "control and
monitor" operations, including:
• Accurate setpoint adjustment flow output measurement
(including units of measure selection)
• Valve Override (controller only)
• Flow Totalizer
• Alarm status and settings
• Soft Start Control (controller only)
Refer to Table 1-3 (Analog I/O pin connections), that enables the device to
communicate via a personal computer for process control. The
communication speed (baud rate) is software selectable.
Baud rate selections for the Brooks SLAMf Digital Series related to RS-485
are: 300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600 and 115200
baud and can be selected via software.
The RS-485 is essentially a multidrop connection. It allows a maximum of
32 devices to be connected to a computer system. IBM-compatible PC's
are not equipped with RS-485 ports as standard. An RS-232 to RS-485
converter or RS-485 interface board is therefore required to connect an
RS-485 network to a standard pc. The RS-485 bus, a daisy chain network,
meaning that the wires are connected at the units as in Figure 1-2.
DeviceNet Communications
The Brooks SLAMf Digital Series is also available with DeviceNet TM
communication capability. DeviceNet is an open digital protocol capable of
high speeds and easy system connectivity. Brooks Instrument has several
of its devices available on this popular networking standard, and is a
member of ODVA
TM (Open DeviceNet Vendors Association), the governing
standard body for DeviceNet.
DeviceNet is similar to the RS485 standard in that it is a multi-drop
connection that allows a maximum of 64 devices to be connected on the
same network. Baud rate selections for DeviceNet
products are 125K,
250K and 500K and can be selected via MAC ID switches mounted on the
device.
The DeviceNet communication link also provides access to many of the
Brooks SLAMf Digital Series functions for “control and monitor” operations,
including:
• Accurate setpoint adjustment and flow output measurement (including
units of measure selection)
• PID Settings (controller only)
• Valve Override (controller only)
• Calibration Gas Select
• Soft Start Control (controller only)