User manual

Toolbox 32 User Manual 1.47d www.cse-semaphore.com/mykingfisher

Page

162

Driver - Modbus

The Modbus driver allows the RTU to respond to and initiate Modbus messages. If the RTU only needs to

respond to messages (eg. from an operator panel or PC) then the Tx Modbus and Rx Modbus ladder blocks

are not used.

Kingfisher RTUs use a data format of 8 data bits, no parity bit and 1 stop bit and support the RTU Modbus

data format. Note: an MC-xx module can also initiate Modbus messages in ASCII format (7 data bits, even

parity and 1 stop bit). Modbus is also supported on processor Ethernet ports (CP-10/11, CP-21).

Tx Modbus

Transmits 16-bit registers or digital channels to a Modbus device.

Comment: A 12-character description.

RTU #: (#R1 to #R2048 or 1 to 249) The destination RTU (or PLC) address. Can be specified as a local

are: #Rxxxx, #Rxxxx.cc where xxxx=local register number (1-2048) and cc=channel number (1-16). Network

registers (#N…) cannot be used. Note: before sending floating point or long registers to a Modbus device,

the 2 Kingfisher local registers used to store the number will need to be reversed. Please see Modbus

Floating Point and Long Registers below for more information.

MODBUS Address: (1 to 49999 or L000001 to L465535 when using extended addressing) The starting

address to store the registers from in the destination PLC (or RTU). The registers are stored at consecutive

addresses starting from the address specified here.

No. of Points: (#R1 to #R2048 or 1 to 123) The number of consecutive 16-bit registers or channels (single

bits) to send. Can be specified as a local register or a constant. If a register bit is specified for Register

above (e.g. #DI3.1, #R1.1) then the Number of Points is the number of bits to send otherwise the No. of

Points is the number of registers (or analog channels) to send. Note: when sending analog channels (#AO or

#AI) every analog module is assigned 8 points and every digital module is assigned 16 points. A multi IO

module with analog channels (such as the IO-4 or IO-3) is also assigned 8 points. Note: two points must be

specified for each float or long that is sent.

Examples: Register Points

1. To send Chs 1-16 of #DI3 and #DI4 #DI3.1 32

2. To send Chs 1-8 of #AI6 and #AI7 #AI6.1 16

3. To send AI Chs 1-4 of IO-3 Modules 14 and 15 #AI14.2 12

Example 3 shown above will send #AI14.2, #AI14.3, #AI14.4, #AI14.5, #AI14.6 (not used), #AI14.7 (not

used), #AI14.8 (not used), #AI15.1 (not used), #AI15.2, #AI15.3, #AI15.4 and #AI15.5. Alternatively, two TX

Modbus blocks could be used that sent 4 points each.