M172 ↔ M171EP14R Expansion limitation

[StevenCho]

Hi there,

I have no idea how to set CAN address that exceeds dip switch combination.

I configured TM172PDG42RI + TM172EP14(5EA).

There is 4 dip switchs on TM171EP14R. 

As I understood, [1],[2] is for setting address and [3],[4] is resistance.

Up to 4th expansion, there is no problem.

But 5th expansion is problem.

With [1],[2] Switch combination, I only can make address '4'.

I tried to set below, but I don't know how to use it correctly.

Anyone who knows how to use it correctly, please😭

[Bastian_Schmitz]

Hi,

if you want to use more then 4 TM171EP14R you need to configer the base address on the fifth expansion via TM171ADMI. You could do this via ESME HVAC installer. The case that a customer need more then 4 TM171EP14R is not really common. But we adjust this point on the newer Expansions which have more adjustable addresses via dip switch. If you configer via ESME HVAC installer and TM171ADMI the base address the address via DIP switch will be added.

[StevenCho]

So to set address '5',

1. Set Addr_CAN_OB(15780) to '2'
   
2. Set dip switch ON from 1 to 4

Is it right?

But how can I connect ADMI with EP14R?

There is no connector for ADMI Cable on EP14R .(Not like TM171ODM14R)

Thank you!

[Bastian_Schmitz · Accepted solution]

The DMI connector is behind the front cover. And yes you need to adjust the address to 2. But be carefull if you use the TM171ADMI on TM171EP14R you need to power up this extension sepratly. But take care that your power supply is not secoundary grounded. Because otherwise you could creat a mass loop which could destroy the TM171ADMI.

[StevenCho]

Perfect! Thank you Bastian🙂

[VaidasM]

Hello, 

we want to use the same configuration of controllers, can line is working, but could not find where to change analog output type to voltage - config value must be  equal to 2, but where to find this config? We are using Machine expert hvac.

Thank you.

[Bastian_Schmitz]

The TM171EP14R did only support 0-10V on the Analog Output. Regarding to this point you must configure nothing in your case.

[VaidasM]

Hello, 

what is the maximum allowed number of M171 can be connected to M172?

Vaidas

[StevenCho]

According to the catalog,

"The maximum number of expansion modules on the CAN expansion bus is 7, in
any combination "

But it seems there is other way to expand more.
There was remark on Catalog like below

"(if more expansions are needed, please contact our Customer Care Centre)."

[Bastian_Schmitz]

There is no hard limitation of Expansion on the CAN Bus. So far I know the maximal limitation in the catalog is a result of the maximum number of Field Variables and these number is qualified from R&D.

If you map the values to status instead to field variables you could add more expansions. I had several years in the past a project with 8 14IO Expansions (Without problems).

In general if you have more expansions the time for variable refreshing will be get bigger. 

In my opinion it would be better, to add less 28IO expansions to reach the number of IOs. If you need a high count of AO, then is 14IO the only solution.