Watts HF scientific SSR-Ex 28037, Руководство по эксплуатации и обслуживанию

Страница: 9 / 20

9
4.5 Modbus Control
In addition to the above mentioned Remote Standby Connections,
control can also be achieved using Modbus control. Two special
Modbus addresses are provided. The reading cycle is initiated using
the Coil Address 00005 with the default at False (0). Setting this
Address to True (1) initiates the reading cycle.
At any time the standby status can be checked at Modbus Coil
Address 00005 or Modbus Input Address 10005. False (0) indicates
standby and True (1) indicates the measurement cycle is taking place.
Control is only available from the Coil Address 00005 for more setting
information refer to Section 4.2.1.4. - Modbus Menu.
The default communication parameters are 8 bits, no parity and 1 stop
bit. Please note that all Modbus communication is via RS-485. The
instruments can support a two wire multidrop network of 255 units. If
the connection is to the master on USB, an RS-485 to USB converter
is required.
4.5.1 Coils
These single-bit values are readable and changeable from the master.
The data will be returned with the lowest addressed coil in the least
significant bit (LSB) of the data. Unused bits in the data will be set to 0.
True is a 1 and False is 0.
4.5.1.1 Valid Command(s)
Code Name Broadcast
0x01 Read Coil Status No
0X05 Force Single Coil Yes
MSB LSB
Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
4.5.1.2 Format
16-bit word format
4.5.1.3 Valid Addresses
00001 – 00XXX
4.5.1.4 Definitions
Address Function Default
00001 NOT USED False
00002 NOT USED False
00003 NOT USED False
00004 Service mode (Go into service mode if true) False
00005 FDI (flag data in)
False means waiting for a command. Standby mode. True means
start a cycle. False
00006 Zero Flag – Zero the reading if True False
00007 Prime mode – Start a prime if True False
4.5.2 Input Status
These single-bit values are readable from the master. The data will be
returned with the lowest addressed input status in the least significant
bit (LSB) of the data. Unused bits in the data will be set to 0.
4.5.2.1 Valid Command(s)
Code Name Broadcast
0x02 Read Input Status No
4.5.2.2 Format
16-bit word format
MSB LSB
Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
4.5.2.3 Valid Addresses
10001 – 10XXX
4.5.2.4 Definitions
Address Function Default
10001 Instrument error False
10002 Instrument error with alarm False
10003 Alarm 1 active False
10004 Alarm 2 active False
10005 FDO (flag for data out)
False means waiting for a command to start. True means
going through a cycle (busy). False
4.5.3 Holding Registers
These 16-bit values are readable and changeable from the master. The
data is stored and transmitted with the most significant bit (MSB) first
and then the least significant bit (LSB).
4.5.3.1 Valid Command(s)
Code Name Broadcast
0x03 Read Holding Registers No
0x06 Preset Single Register Yes
0X16 Preset Multiple Registers Yes
4.5.3.2 Format
Float – stored in two consecutive addresses, with the first address
containing the least significant word (lower part of mantissa) and the
second address containing the most significant word (sign, exponent,
and upper part of mantissa).
4.5.3.3 Valid Addresses
40001 – 40XXX
4.5.3.4 Definitions
Address Type Register Min Default Max Function
40001 Int NOT USED 0 0 0
40002 Int Units (scaling) 0 0 1 0 – PPM
1 – MG/L
40003 Int Readings Per Average 1 2 5 Number of readings
used for averaging
40004 Int LCD backlight 10 80 100 Percent. Higher is
brighter
40005, 40006 Float 4-20 mA minimum
value
0.0 0.00 15.0 Scaling value
40007, 40008 Float 4-20 mA maximum
value
0.0 15.00 15.0 Scaling value
40009 Int 4-20 mA error alarm
output 0 2 3 0 – Off
1 – 0 mA
2 – 2 mA
3 – 4 mA