A8814 Acq
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Check to verify the Modbus device is supported by the AcquiSuite. Usually, the AcquiSuite will locate the
device and print “Unknown” in the device status column if the device is not recognized by the AcquiSuite
firmware drivers. In the lower right corner of this screen, there is a link that will show a list of supported
devices. Use this to verify the Modbus device in question is supported by the AcquiSuite firmware version. If
not, check for firmware upgrades online with the Firmware Update configuration page.
Remember, the AcquiSuite may take between 2 and 5 minutes to detect a new device that has been attached
to the Modbus rs485 loop. Rebooting the AcquiSuite, refreshing the device list page, or using the console
'Modbus status' menu will not speed up the recognition process.
Click the “Troubleshooting” link at the bottom of the Modbus device list page for further diagnostics.
Modbus Setup
The Modbus setup page provides several options related to the Modbus RS485 serial port.
AcquiSuite Name:
This is the name of the AcquiSuite. This name will be present on all log file descriptors when
uploaded to a central database website such as BMO. It is helpful to name the AcquiSuite based on the physical
location of the system, or building. Note: this feature was labeled “Loop Name” in older firmware versions.
Data logging period:
This option sets the log interval for the AcquiSuite. Options range from once per minute to
once per hour. All of the selections are even divisions of one hour. The AcquiSuite calculates the next log time
by finding the next multiple of the log period past the start of the hour. For example, if the log period is 15
minutes, log readings will be taken at 0, 15, 30 and 45 minutes past the hour. The log period is not calculated
based on “15 minutes after the last reading”
When the AcquiSuite is first started, it will take an initial reading of all the Modbus devices immediately.
Following that, the next log reading will be calculated as a multiple of the log period after the hour. The initial
reading is taken to allow the AcquiSuite to gather information for meters that require demand calculations, as
well as provide accurate information starting when the AcquiSuite is booted.
Modbus/TCP access:
The AcquiSuite has a Modbus TCP gateway feature that allows other systems to send
queries to all attached Modbus RS485 devices. This feature allows control of what systems have access to the
Modbus TCP gateway feature. The settings include “no access”, “local subnet only” and “allow any”. This basic
security feature only allows control based on the IP address of the system making the request. The Modbus TCP
protocol does not have provisions for any authentication password or other methods of security. By default, the
gateway feature is disabled, and set to “No Access.”
The Modbus TCP gateway is a feature that allows the AcquiSuite to share the attached Modbus RS485 devices
with other systems such as PCs with software and building control systems. The gateway receives incoming TCP
requests, verifies the length of the packet does not exceed 255 bytes, and forwards the packet to the Modbus
RS485 loop. The gateway does not verify the contents of the packet, nor the target address specified in the
request. If the Modbus RS485 device sends a valid response back, the gateway will return this information to
the the system requesting it via TCP. If no response is received, a timeout failure will be sent to the requester.
Because the gateway does not process the contents of the request or reply, it is possible to query devices on the
Modbus RS485 loop that are not specifically supported by the AcquiSuite. A Modbus/TCP technical guide may
be available soon at www.obvius.com.
Modbus RS/485 baud rate
: This feature allows the configuration of the RS485 serial port speed which the
AcquiSuite uses to communicate with Modbus devices. Options include
9600
,
19200
,
38400, 57600,
and
115200
. The default is 9600, most Modbus devices communicate at this speed as well. Multiple baud rates may
be selected in this menu. If multiple rates are selected, the AcquiSuite will automatically detect the baud rate of
each Modbus device from the chosen options. Once the baud rate has been detected for a specific Modbus
device address, and will continue to communicate with that specific device address at the detected speed. This
feature will allow you to mix multiple devices on the same RS485 loop with different baud rates. Modbus
devices default to a baud rate of 9600. Note: Modbus device manufacturers usually do not 'officially' support
