Dwe_ - Digital Write Ethernet - Siemens 353 User Manual

Function Blocks

3.2.35 DWE_ - Digital Write Ethernet

DWE_ function blocks use Modbus command 16
"Preset Multiple Registers" to enable the controller to
write a word, based on 16 discrete inputs to the
function block, to other stations over the Ethernet
network.
Up to 32 DWE_ blocks are available. Blocks are
assigned in sequence, controller wide, with each use.
Digital data is On/Off data packed into a 16-bit word.
The IP ADRES parameter is used to configure the IP
address of the destination Modbus/TCP device. The
MB ADRES parameter allows a Modbus address to be
configured. When connecting to other Siemens
controllers the Modbus address is set to 1. In some
cases, other Modbus devices may use a different
address or, when going through a Modbus/TCP
gateway, a Modbus network may have multiple
devices, each having a unique address. The MB REG
parameter identifies the location of the register in the
Modbus device.
There are three write update options that can be
configured by the UD TYPE parameter.
1. oncE will write once to the START CL (Modbus
Starting Coil. The controller will write when any
block input value changes state.
2. P2P will update at the controller peer to peer rate set in the ETHERNET block.
3. Ct will update at the cycle time of the controller.
The Ct option is normally used only when writing time critical changes. Input T can be used to trigger a write. This
would be used in cases where the oncE option has been selected, input values do not change, and there may be a
concern that the receiving device has lost the values.
Output QS indicates the quality of the write operation and will go high (1) when the write is not completed
successfully. This is normally associated with failure of the destination device to receive data due to a
communication failure or a misconfiguration of the device.
3-40
DIGITAL WRITE - ETHERNET
DWE_
Input 0 0
Input F F DIGITAL WRITE
ETHERNET
Input T
T
Quality Status
QS
I N P U T 0
INPUT 0
(H)
I N P U T 1
INPUT 1
(H)
I N P U T 2
INPUT 2
(H)
I N P U T 3
INPUT 3
(H)
I N P U T 4
INPUT 4
(H)
I N P U T 5
INPUT 5
(H)
I N P U T 6
INPUT 6
(H)
I N P U T 7
INPUT 7
(H)
I N P U T
8
INPUT 8
(H)
I N P U T 9
INPUT 9
(H)
I N P U T A
INPUT A
(H)
I N P U T B
INPUT B
(H)
I N P U T C
INPUT C
(H)
I N P U T D
INPUT D
(H)
I N P U T E
INPUT E
(H)
I N P U T F
INPUT F
(H)
I N P U T T
INPUT T
(H)
I P A D R E S
IP ADdRESs
M B A D R E S
MB ADdRESs
M B R E G
ModBus REGister
U D T Y P E
UpDate TYPE
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.....................
nnn.nnn.nnn.nnn
(H)
(192.168.0.0)
................................... 0 - 255
(0)
(H)
......................... 1 - 65535
(1)
(H)
......................... oncE/P2P/Ct
(oncE)
(H)
April 2012