Tecnetics Industries Tecweigh 20, Operation Manual

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8.01 Overview
The WP20's RS232C and RS485 serial communications interfaces allow remote computers and
PLC’s to access RATE, TOTAL, SPEED, and Status data, in addition to requesting basic
calibration functions. The WP20 can be configured to send data either automatically (every 1/10
second fixed) or upon request (manually). If sending data automatically, only one unit can be
used per serial link. The automatic mode is commonly used for sending Rate and/or Total to
display devices. When requesting data manually, 16 units can be multi-dropped on one serial link
and each unit is identified using capital letters A to P. The characters used are ASCII. Wire the
serial communications per Section 4. Configure the Parameters per Section 6.02.41-45.
Note : When setting up serial communications the message “FRAMING ERROR” might appear
in the MODE window. This indicates that a Parameter setting is incorrect. Assure that all serial
communications related Parameters are correct for the system -- Station ID, Parity, Baud Rate,
Command Menu, and Protocol (See Sections 6.02.41-45).
Important: The plant remote equipment must also be operating with the exact same serial
communications settings (mutually compatible) for the system to operate properly.
8.02 Automatic Transmission
When a Command Menu Parameter (selected from the following table) other than 00 is entered
into the WP20, it will send the selected data automatically every 1/10 second. For example, if the
Command Menu is set to 04, the WP20 will transmit the RATE and TOTAL every 1/10 second.
Command Data
Menu Transmitted
00 (Used for manual data transmission only, see section 8.03)
01 RATE
02 TOTAL
03 SPEED
04 RATE, TOTAL
05 RATE, SPEED
06 Average RATE
07 Average SPEED
08 Average RATE, TOTAL
09 Average RATE, Average SPEED
10 Status
11 RATE, Status
12 TOTAL, Status
13 SPEED, Status
14 RATE, Status, TOTAL
15 RATE, Status, SPEED
16 Average RATE, Status
17 Average SPEED, Status
18 Average RATE, Status, TOTAL
19 Average RATE, Status, Average SPEED
20 Send RATE in FC20 set point mode. See FC20 manual.
CHAPTER 8 - SERIAL COMMUNICATIONS