User guide

eWON 500-2001-4001-4002 User Guide - IO Servers Configuration
eWON 500®2001®4001®4002® Version 4_3_0 - User Guide - 10/5/05 - ©ACT'L sa - Page 80
6.3.2.4.1 Additional advanced parameters
Some parameters don’t display in the Modbus IO server configuration window:
• gwdestaddr
When the eWON is used as a Modbus gateway, it uses the UnitID from the ModbusTCP request to determine the Modbus RTU destination
address.
It is possible to bypass this mechanism and force all requests received by the eWON in ModbusTCP to be forwarded to a single ModbusRTU
device (EXCEPT for requests with UnitID corresponding to the eWON's Modbus TCP Unit address
(usually 100) when the eWON Server is enabled - see explanations about this precise point in the above configuration fields descriptions).
Every requests are forwarded to the device with Slave address defined by the Modbus IO server advanced parameter called gwdestaddr.
If the advanced parameters textfield contains the following entry:
gwdestaddr:10
Then all requests will be forwarded to the slave with address 10.
REMARK: the eWON will change the address before sending the request to the slave, then it will change it back when sending the response to
the master (Modbus TCP master). So the gwdestaddr will never appear in any communication between the Master and the eWON.
• FastSrv
FastSrv is a mode which allows a supervisor to read in Modbus TCP more easily the Modbus tags published by eWON.
This mode completely changes the tag’s addressing, and when activated, the Modbus addresses are no more compatible.
You have just to enter “FastSrv:1” in the Advanced Parameters text area to activate it. When done, the Modbus tags can be read as follows:
Notes:
• If the tag is binary read, its value is worth 0 if tag==0, and 1 if tag <>0
• Writing 0 in AlarmStatus acknowledges the alarm (will be logged by eWON as acknowledged by administrator)
• It is not possible to write a coil in the float area (coil address range: X+2048 to X+4094)
• It is not possible to address more than 1024 registers in float.
Click the Update Config button to validate your inputs or use the Cancel button to discard changes
Parameter name Description
PreDelayFrom
Used in conjunction with the next parameter (PreDelayVal), starting at that slave address, the
eWON will insert a delay when switching from one slave address to another. If the
PreDelayVal feature is not used, then the value for PreDelayFrom must be set to 256.
PreDelayVal
Used to define the delay (in Msec) to be inserted before request to a slave if previous request
was sent to another slave address (not between 2 requests to the same slave). The
PreDelayVal is place only for slaves with an address higher than PreDelayFrom. (in Msec)
ErrorRetry Defines the number of errors before the device enters in slow poll mode. (Minimum 1)
SlowPollSkip
Defines the number of times the slave is skipped when in slow poll mode. This delay depends
on the poll rate.
GatewayIPCTimeout
Maximum event lock while waiting for response to modbus gateway request from the modbus
IO server (router) (in Msec – minimum 1000).
PostErrorDelay
This delay is added each time a device responds with a framing error or a CRC error, in order
to help the bus to perform its re synchronization. (in Msec)
MaxDeltaCoilX (X= A,B,C) Maximum number of Coils that can be grouped in a request (per topic)
MaxDeltaRegX (X= A,B,C) Maximum number of registers that can be grouped in a request (per topic)
Table 51: extended IO server configuration controls
X Integer (with scale factors and offset defined)
X+2048
Float (X+2048: 1
ST
float, X+2048+2: 2
nd
float, etc.)
X+4096 Alarm status
X+6144 Alarm type