Altronic DD-40NTS-O, Руководство по установке

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D. LOADING - RS-485 uses a balanced differential pair of wires switching from 0 to 5 volts
to communicate data. In situations where many units (99 max.) are connected together
on a long run, voltage drop on the communications leads becomes a major problem.
Voltage drops on the RS-485 minus lead appear as a common mode voltage to the
receivers. While the receivers are rated to a maximum voltage difference of +/
!
7 volts,
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7V to +12V, a practical system should not have a voltage difference exc/
!
3
volts under normal conditions. The wire gauge used for the connections therefore limits
the maximum number of units or the maximum length of wire between units in each
application. The following formula can be used as a guideline to select the appropriate
wire gauge.
For 18 AWG wire No. of annunciator units = (4000) / (ft of wire used)
For 20 AWG wire No. of annunciator units = (3600) / (ft of wire used)
For 22 AWG wire No. of annunciator units = (2400) / (ft of wire used)
NOTE: The maximum number of units connected together in a system is 99.
8.8 RS-232 COMMUNICATIONS
A. For proper operation, the wire length should not exceed 50 feet.
B. Use standard DB-9 connector and computer cable, Altronic no. 693 116-x or equivalent.
8.9 MODBUS STRUCTURE - The annunciator can operate as a Modbus RTU slave. A
command must be transmitted to the unit by the master (computer or PLC) before the slave
can respond with useful data. A slave unit can never initiate a communications sequence.
Select the Modbus communications option. See section 4.8. Communication to the
annunciator can then be performed using standard Modbus RTU protocol. Multiple register
reads are supported, specify number of registers.
Register (16 bit binary register value)
40001 RPM ( 0-2500 )
40002 Hourmeter hours ( 0-65535 )
40003 Class B1 timer ( seconds )
40004 Shutdo wn S tatus ( 0 = O K, 1 = Fau lt )
40005 Outpu t Status ( bit 0 = SW 1, bit 1 = SW 2, 1 = tripped, 0 = running )
40006 Input ( chan. 10-27; bit 0 = 10, bit 8 = 20, bit 15 = 27 )
40007 Input ( chan. 30-47; bit 0 = 30, bit 8 = 40, bit 15 = 47 )
40008 Input ( chan. 50-57; bit 0 = 50, bit 7 = 57, bit 8 = ovrspd, bit 9 = loss of sp d)
Inpu t OK = 1, Inp ut Fa ult = 0; 40 006 , 400 07, 4 000 8 all FF for ru nning O K.