Modbus EPICS IOC for NTI E1W

This repository is only for an example, we decided not to use this product due to unknown Modbus connection stabilities. I didn’t catch up their latest firmware also.

If one needs many temperature monitoring channels, I recommend to check the Measurement Computing TC-32 unit.

NTI E1W [1] is the low-cost environment monitoring system with 1-wire temperature over Modbus TCP/IP. The NTI E1W also supports the SNMP, but I don’t test it yet.

It supports 24 single reading 1-wire sensors in any combination, but this example only has 8 temperature sensors.

Requirements

EPICS BASE
Asyn R4-40
Latest EPICS modbus 54cea0d (Probably R3-1) : The version of Modbus should support FLOAT32_LE_BS [2].

Firmware

Firmware revision should be larger than 3.2, because from the firmware 3.2, E1W supports MODBUS protocol. The firmware 3.3 or latest one is recommended.

Build

With the standard EPICS building system, please run make

Run

./cmds/E1W.cmd

Check PVs

 $ bash scripts/caget_pvs.bash -l LBNL_OneWireIOC_PVs.list
>> Selected PV and its value with caget
LBNL:OneWireIOC:E1W-E02-01-DigitalInput-RB 0
LBNL:OneWireIOC:E1W-E02-01-Temperature-RB 26.875
LBNL:OneWireIOC:E1W-E02-02-DigitalInput-RB 0
LBNL:OneWireIOC:E1W-E02-02-Temperature-RB 25.125
LBNL:OneWireIOC:E1W-E02-03-Temperature-RB 93.3125
LBNL:OneWireIOC:E1W-E02-04-Temperature-RB 23.625
LBNL:OneWireIOC:E1W-E02-05-Temperature-RB 78.0125
LBNL:OneWireIOC:E1W-E02-06-Temperature-RB 78.6875
LBNL:OneWireIOC:E1W-E02-07-Temperature-RB 80.0375
LBNL:OneWireIOC:E1W-E02-08-Temperature-RB 79.925
...


Figure 1 Phoebus Screen.

References

[1] http://www.networktechinc.com/environment-monitor-1wire.html

[2] https://github.com/epics-modules/modbus/pull/20