Endress+Hauser WirelessHART Fieldgate SWG70 - Digital Input;Output Devices

Modbus Interface WirelessHART Fieldgate SWG70
120 Endress + Hauser
16.2.2 Digital input/output devices
There is no automatic mapping of the Input Status registers. the user must generate the
mapping table either semi-automatically or manually.
• A semi-automatic mapping will duplicate the values entered under the "Generate" tab for
all devices in the network, irrespective of device type
• A manual mapping allows the table to be built up for each individual device
(recommended)
Discrete devices publish their values by "bursting" HART CMD 64386. This tells Fieldgate
SWG70 how many discrete values a device has as well as the index of the first discrete value.
A maximum of 256 discrete values can be mapped for each device. At the moment, Fieldgate
SWG70 does not map the status of the device.
Each discrete value is published as a UNIT16. Fieldgate SWG70 first splits the data into two
bytes then reserves 8 registers for each byte, i.e. one for each bit.
• The Least Significant Byte (x) maps Bits 0 - 7 of the value with Index x
• The Most Significant Byte (x) maps Bits 8 - 15 of the value with Index x
Index "x" is not determined by the position of the discrete value in the device burst list but
rather by its position in CMD 64385. For example, if the 1st and 4th discrete variables are
selected in the burst list, the corresponding indexes are "0" and "3". Assuming that all bytes
are of interest, the user must enter the following lines:
• Tag Device 1: Least Significant Byte0
Tag Device 1: Most Significant Byte 0
Tag Device 1: Least Significant Byte 3
Tag Device 1: Lost Significant Byte 3
The following (manual) mapping table results:
When Fieldgate SWG70 receives CMD 64.386, it checks whether the variables have been
mapped, then enters the associated information. Any values that are not mapped are
discarded.
Reference address Device Discrete Variable Bit Byte (Variable Index)
100001 Device 1 Variable 1 Bit 0 LSB (0)
100002 Device 1 Variable 1 Bit 1 LSB (0)
...
100007 Device 1 Variable 1 Bit 6 LSB (0)
100008 Device 1 Variable 1 Bit 7 LSB (0)
100009 Device 1 Variable 1 Bit 8 MSB (0)
100010 Device 1 Variable 1 Bit 9 MSB (0)
...
100015 Device 1 Variable 1 Bit 14 MSB (0)
100016 Device 1 Variable 1 Bit 15 MSB (0)
100017 Device 1 Variable 4 Bit 0 LSB (3)
...
100025 Device 1 Variable 4 Bit 7 LSB (3)
100026 Device 1 Variable 4 Bit 8 MSB (3)
...
100032 Device 1 Variable 4 Bit 15 MSB (3)
...